Project Helpers

2014-02-03T05:12:00.003+07:00

Physics Questions and their answers:

Q1.

A thin glass rod is bent into a semicircle of radius r. A charge +q is uniformly distributed along the upper half, and a charge of -q is distributed along the lower half, as shown in Fig. 23-34b. Find the magnitude and direction of the electric field E at P, the center of the semicircle.

(a) The magnitude of the electric field at P is:

q / (²*₀*r²)
q*r² / (²*₀)
-q*r² / (²*₀)
q / (2**₀*r²)
q*r² / (*₀)

(b) The direction of the electric field at P is:

Vertically upwards
Vertically downwards
Horizontally to the right
Straight out of the computer screen
Straight into the computer screen
Horizontally to the left

Answer: 2. Vertically downwards

Please Leave Your Comments And Your Queries/Doubts In The Suggestion Box. Please Provide Some Suggestions About Other Topics Of Essay. Follow my blog to get a lot of information and help,

To determine the percentage of chloride ions in average sea water.(DCP)

2012-06-13T21:16:00.000+07:00

Aim:

To determine the percentage of chloride ions in average sea water.

Procedure:

1. Collect the provided sample of seawater which is to be analyzed.

2. Requires titration of the solution.

3. In the Burrete contains the silver nitrate.

4. In the conical flask below, take 25 ml of seawater with a pipette and add few drops of indicator.

5. Add the silver nitrate until the indicator changes color slightly. (this case: changes yellow to red)

6. Note the difference and analyses.

DATA COLLECTION & PROCESSING

During the experiment, there was a visible change, which is a part of the qualitative data, and there was a numerical change also. Therefore the qualitative analysis is listed below:

Qualitative Analysis:

Before Reaction:	During Reaction:	After Reaction:
The burrete was colorless with only silver nitrate in it. The conical flask contained a yellowish solution which was a mixture of colorless seawater and yellowish indicator of potassium chromate.	During the addition of the silver nitrate into the flask, slight reddish change would occur but soon would dissolve back to yellowish color. This usually changed back due to shaking of the flask.	The burrete was closed as soon as there was a permanent light reddish precipitate in the flask. This meant that all the reaction is over and there was a mere excess of the silver chloride added.

Quantitative analysis:

The data recorded during the practical is as follows:

Raw Data:

Trial number	Initial meniscus(±0.5)	Final Meniscus(±0.5)
1	50	23.1
2	30	2.7
3	30	3.3

Processed Data:

Trial number	Initial meniscus (±0.5ml)	Final Meniscus(±0.5ml)	volume of silver nitrate(±1ml)
1	50	23.1	26.9
2	30	2.7	27.3
3	30	3.3	26.7
Average			26.97

Calculations:

The difference to find the volume of silver nitrate used: initial volume – final volume =

50 ml – 23.1 ml = 26.9 ml (first trial data)

Uncertainty of the difference:

∆V1+∆V2 = 0.5 ml +0.5 ml = 1ml

Therefor the volume of the silver nitrate used in the first trial is: 26.9 ml ± 1ml

Average: (sum of data of all the trials)/ number of trials = (26.9+27.3+26.7)/3 = 26.9666≈26.97

Uncertainty: (∆V1+∆V2+∆V3)/3(mean deviation)= (1+1+1)/3 = 1 ml

Average volume used: 26.97ml ± 1ml

________________________ ______________________________

Thus now we have the volume of the silver nitrate, so now we will deduce the main aim of determining the percentage of chlorine present in the seawater.

Conversion factor:

1 ml ≈ 1cm³

Thus, 26.97ml ± 1ml ≈ 26.97 cm³ ± 1 cm³

Uncertainty : 1/26.97 *100 =3.7%

Number of moles of silver nitrate calculation:

Concentration = 0.05M

C=n/V

Thus, n = CV

so, n= (0.05Mx26.97dm3)/1000

n=0.0013485 moles

Number of moles of silver in 1 moles of silver nitrate: 1 (Agno3 has 1 Ag)

Number of moles of silver in 0.0013485 moles of silver nitrate = 0.0013485 moles

The reaction between Chlorine and silver nitrate:

Ag+ + Cl- >>AgCl

Thus ratio is 1:1

Therefore moles of chlorine ions used: 0.0013485 moles

And therefore the mass of chlorine used: Mr *n = 35.5g/moles x 0.0013485 moles = 0.04787 g

Therefore thee concentration of chlorine in seawater: 0.04787g/0.025 dm3 = 1.91487g/dm3≈1.91gdm^-3

Uncertainty: 3.7% of 1.91 = 0.07 g dm^-3

Thus, the concentration of chlorine is : 1.91gdm^-3

The average concentration of the seawater is: 1.025 g/ml = 1025g dm^-3 (taken from: http://en.wikipedia.org/wiki/Seawater)

Thus the percentage of chlorine = 1.91gdm^-3/1025g dm^-3x 100= 0.186% = 0.19%

Therefore the chlorine percentage in seawater is 0.19 %

_____________________________________________________________

Please Leave Your Comments And Your Queries/Doubts In The Suggestion Box. Please Provide Some Suggestions About Other Topics Of Essay. Follow my blog to get a lot of information and help,

The purpose of this experiment is to determine if gender in tenth graders affects resting and jogging pulse rate.

2011-06-04T17:30:00.001+07:00

Problem:

The purpose of this experiment is to determine if gender in tenth graders affects resting and jogging pulse rate.

Background

Factors affecting heart rate:

Size: the larger the size, the slower the rate. For example, a grizzly bear has a heart rate of about 30 beats a minute while a hummingbird’s is about 200 beats per minute.
Gender: a woman's heart rate is generally faster than a man's.
Age: generally the younger a person is, the faster the heart rate. An infant's heart rate is about 120 beats per minute; a child's is around 100; an adult's is between 70 and 80; an elderly person generally hovers in the 60s.
Exercise: temporarily increases the heart rate.
Stimulation of the autonomic nerves.
Hormones: influence heart rate, especially epinephrine, norepinephrine, and thyroid hormones, all of which can increase the rate.
Pathology: certain diseases affect heart rate, causing it either to slow or to race. Either one sets the stage for further dysrhythmias.
Medications and drugs: For example, digitalis slows the rate, while epinephrine (Adrenalin) increases it. Caffeine can also cause palpitations or extra beats.

(Copied from the website http://www.innvista.com/health/anatomy/pulse.htm visited on 22/08/2010)

HYPOTHESIS

My hypothesis is that a tenth grade female’s pulse rates will be higher than the male’s pulse rates. It is based on the words: “Gender: a woman's heart rate is generally faster than a man's.”

Variables:

Independent: The gender and the exercise
Dependent: Pulse rate at that point
Constant:

1. Age group of subjects (in years)

2. BMI (same group)

3. Location (brachial) where the pulse is taken.

4. The number of test subjects from each gender

5. The state of the body at the particular time(sitting for two minutes and jogging for two minutes)

Manipulation of the Variables:

The manipulated variable was the gender of each test group. As the gender changes the pulse should change. As the research says women have slightly higher pulse rate. The second manipulated variable was the exercise. The responding variable was the number of beats per minute in each gender. To measure the responding variable I will take the brachial pulses of each subject three times, find the mean of the two separate genders and find the differences between each gender. (the jogging and resting is just used as crosschecking whether females have higher B.P.M. than males.

Materials:

Quantity	Amount
5	Grade 10 Male students
5	Grade 10 Female students
1	Chair
1	Stopwatch/Watch

Diagram

Procedure:

1. First gather permissions from the test subjects

2. Then one by one bring the test subjects for the investigation

3. Each would sit for two minutes

4. Then their pulse rate would be taken for two minutes and then divided by two.

5. After this the subject would be told to run for two minutes

6. Their pulse rate would be taken for thirty second.

7. For each subject the test would be conducted on the same day

8. The next two days again they would be called and would repeat the steps from 3-7.

9. The average would help us analyse whether our hypothesis was correct and give a more reliable conclusion

Safety Precautions:

Few safety measures should be kept in mind:

· The person should not be hyper or sad or any such emotion. The emotions can really affect the heart rate

· The person should not have any kind of bleeding or wound, it can affect pulse rate speeding it up

· He/she should not be fasting or having diet control (applies for diet controllers and religious believers)

DATA PROCESSING

BMI: All are in range of normal band(from 18.5 to 24.9)

Resting:

The recorded data:

MALE
Subject:	TRY 1	TRY 2	TRY 3	Average
Subject a	79	81	78	79.33
Subject b	83	80	84	82.33
Subject c	81	82	79	80.67
Subject d	74	72	75	73.67
Subject e	79	78	80	79.00
Subject f	84	85	82	83.67
Average of all the males:				79.78
FEMALE
Subject:	TRY 1	TRY 2	TRY 3	Average
Subject 1	86	85	86	85.67
Subject 2	84	82	85	83.67
Subject 3	79	79	82	80.00
Subject 4	88	89	86	87.67
Subject 5	85	84	84	84.33
Subject 6	83	84	83	83.33
Average of all the females:				84.11

RESULTS

Originally the problem was to investigate if gender affects the tenth grade resting and jogging pulse rates.

The results of the experiment were that the overall B.P.M. of the females was in fact higher than the males by four beats. The overall female average was 84.11 B.P.M. and the overall for males was 79.78 B.P.M.

See graph below:

Jogging:

The recorded data:

MALE
Subject:	TRY 1	TRY 2	TRY 3	Average
Subject a	116	114	118	116.00
Subject b	107	110	105	107.33
Subject c	105	103	106	104.67
Subject d	100	108	105	104.33
Subject e	110	105	115	110.00
Subject f	121	123	119	121.00
Average of all the males:				110.56
FEMALE
Subject:	TRY 1	TRY 2	TRY 3	Average
Subject 1	120	125	122	122.33
Subject 2	128	130	124	127.33
Subject 3	127	128	126	127.00
Subject 4	126	123	128	125.67
Subject 5	122	119	126	122.33
Subject 6	125	124	128	125.67
Average of all the females:				125.06

RESULTS

Originally the problem was to investigate if gender affects the tenth grade resting and jogging pulse rates.

The results of the experiment were that the overall B.P.M. of the females was also higher than the males by fourteen point five beats. The overall female average was 125.05 B.P.M. and the overall for males was 110.56 B.P.M.

See graph below:

A data can also be derived comparing the B.P.M. affected by resting and jogging:

Subject	Rest B.P.M.	Jogging B.P.M.	Increase
Subject a	79.33	116.00	36.67
Subject b	82.33	107.33	25.00
Subject c	80.67	104.67	24.00
Subject d	73.67	104.33	30.67
Subject e	79.00	110.00	31.00
Subject f	83.67	121.00	37.33
Subject 1	85.67	122.33	36.67
Subject 2	83.67	127.33	43.67
Subject 3	80.00	127.00	47.00
Subject 4	87.67	125.67	38.00
Subject 5	84.33	122.33	38.00
Subject 6	83.33	125.67	42.33
Average	81.94	117.81	35.86

A graph illustrating the above data is:

Results

The results of the average show that when a tenth grader jogs his/her pulse rate increases by 35.86 B.P.M. from the normal. Thus if we run or jog for about two minutes the general pulse rate would increase by so much.

Conclusion

My hypothesis was that the female pulse rates would be higher than the males’ pulse rates.

The results indicate that this hypothesis should be accepted. This is because the female overall average was 84.11 B.P.M. and the males’ overall average was 79.78 B.P.M. This indicates that on average 10th grade females B.P.M. are 4 beats higher than the male B.P.M at rest. After jogging, overall female B.P.M. was 125.05 and the overall for males was 110.56 B.P.M having a 14 beats difference. It is clear that my hypothesis was correct. Also it shows that when we jog, for this specific band the beats increase by a large number.

This was for the normal band which proves that girls of grade ten have a higher pulse rate than the female; however I wonder how other bands of BMI would have difference in and how B.P.M. would differ in athletes.

Evaluation:

The investigation went quite well however there were few drawbacks which being a grade ten student was not possible to meet. Firstly the controlling of variables was the toughest. Specially because each person has different metabolism and body structure and unique so controlling their emotions the pace at which they run was not controlled. And more over the sample was small compared to the millions of people in this world. BMI was categorised in a band which could have been a specific number if the total students in grade ten of my school having the age of 15 was hard to get. The data interpreted and analysed will not be that accurate and useful but would give a general idea. Because of shortage of time I couldn’t create a more effective report, but now I have a better idea in this topic so if I were to conduct this project again I would have a larger sample size so I could improve the accuracy rate of this experiment and of a different BMI band so that I can compare these two data.

Please Leave Your Comments And Your Queries/Doubts In The Suggestion Box. Please Provide Some Suggestions About Other Topics Of Essay.

When Rain Clouds Gather

2011-06-04T17:23:00.000+07:00

CHAPTER 8
Paulina revealed
ANALYSIS

This chapter talks mainly about Paulina, her character, her thoughts etc. Along with it there is emphasis on certain themes. We, the readers, also get to know the other personalities more like Maria and Makhaya. There are no antagonistic acts in this chapter and so I would like to call the chapter Paulina revealed.

Being a person with strong mental and physical abilities she has a strong personality. This was clearly visible in this chapter because she was leading the tobacco plantation along with Makhaya and also it was her who made the plantation stable, as gilbert thinks: ‘she was invaluable to him, and without her energy and initiative nothing would start,’(page 123, 2^nd paragraph). However she was weak in one aspect in her life which was love affairs. This was depicted from the lines ‘she was physically alive woman and she was also physically frustrated, and what she needed was someone who could end this frustrations” (page 116, 1^st paragraph) other than this she was also good in arguing with people and would always win at last. Other than this she was a caring mother as she knit up a complete cap for her son as soon as she got to know he would cough every day. Like everyone else in Golema Mmidi, she had her own views regarding foreigners. She says that when you are in a different place, you have to blend in. This was understood from the quote she gave ‘When you are in Rome, you must do as the Romans do?’ (pg. 113).

In this chapter we also come across other personalities like Maria and Makhaya. Within this chapter there are no antagonists as stated before, however this chapter tells us about the hard work the protagonists are doing and also about their characters. We learn more about Maria in this chapter. We can see that she is a smart person, because she handles situations greatly. This was proved when we see, she withdraws from the verbal fight between her and Paulina and also when we said “I haven’t smoked cigarettes… and women who do aren’t brave. They are only boaster.”(pg. 122). This statement proves that she doesn’t believe in false pride or bravery whereas Pauline believes in it because she says she is one of the smokers and is brave for she smokes. Maria however has changes in thoughts often, that’s why it was described in the book that “she had been known to say grass is green one day and then flatly announce that it was yellow on the next”(pg. 121). But it is also know that she understands men, because she explained the truth to Pauline that Makhaya doesn’t like goat meat and sour milk, even though he disagrees to that statement.

Few themes are also shown in this chapter; especially the topic of the relationship between a man and woman is repeated constantly by Paulina. Women were regarded inferior to men and that’s why all ladies were startled when Makhaya spoke to them equally. More-over we can also notice that Paulina was addressing Makhaya as Sir when she asked him for lunch. However we can even see one more aspect that Paulina stated was about hard work. She said “No men ever worked harder than Botswana women”(pg. 108) this also depicts the theme of Hard work done by the village people for their living,, and this is also connected to their main attitude of working hard to make life better. That’s why all the ladies together are working for tobacco plantation.

Slight glimpse of another them was noticed which the child’s role in their daily lives was. First we see a girl who would happily accept money for mistreating her, then we can see in other chapters that a small girl created a connection between a man and woman and now we can see that a small girl is making a miniature village treeless, like barren land like the conditions of Golema Mmidi where Makhaya and Gilbert make up some trees which foreshadows that they would be responsible for the day when the village is a green, happy village with no poverty or mistreatment.

However Bessie Heads’ general theme is still portrayed here where the protagonist is very good and pure. Makhaya in this case is told have a magical personality, who takes away the sadness in us even though himself he has a flat motionless hardworking body. He has a good goal of a happy ending of having children and a family. He is responsible for teaching all the ladies the plantation techniques and also helps them in it. The second protagonist also is shown to have great thoughts, like “this shed meant the difference between having no money and capital to set up a network of bone holes reservoir in Golema Mmidi.”(pg. 118).

There are not many changes in the settings. It was the tobacco plantation and Paulina’s house. The only place which was interesting was the miniature village which was the view of the complete village all together. With all this improvement in characters and settings we hope to read a better tomorrow for all the characters and their ambitions. Thank you all for listening.

Please Leave Your Comments And Your Queries/Doubts In The Suggestion Box. Please Provide Some Suggestions About Other Topics Of Essay.

To investigate any one of the many factors affecting the rate of heat loss of a liquid. My factor: Surface Area

2011-04-20T22:18:00.000+07:00

Reason of Experiment: To investigate any one of the many factors affecting the rate of heat loss of a liquid. My factor: Surface Area

Hypothesis: I hypothesis that if the base surface area of the container is increased, then the rate of cooling would be higher.

This is because: Higher surface area, results in larger area being exposed to the surrounding. The surrounding being cooler or less energised will get energised or absorb heat away quicker from the liquid. Thus the liquid will get cold faster and so rate of cooling will increase. (Provided other factors are kept constant)

Variables in this experiment:

Independent Variables: The surface area

Manipulation of variable: this is the independent variable for my investigation, which I would vary to find the result. This I would vary by changing the container I would place the liquid in. each of them would have a different base area.

Dependent Variable: The temperature change per minute

Manipulation or the dependent variable: this is the variable of my investigation and this result I would gather by checking the temperature every minute for each container holding the liquid.

Constant Variable:

1. Initial temperature:
Manipulation of the above constant variable: this is one of the factors which affect the rate of cooling down,( for example, if the initial temperature is higher, then the rate of cooling is faster at the starting few minutes). This variable can be kept constant by using the same heated water together at the same time, so the initial temperature is kept constant, or wait till the water cools down to a certain temperature.

2. Surrounding temperature:
Manipulation of the above constant variable: this is also a variable which can affect.(if the surrounding temperature is high then the rate of cooling is slow, as the air molecules are already energised. This can be kept constant by doing the experiment in the same room at the same time or by using a water bath.

3. The liquid used:
Manipulation of the above constant variable: each liquid has its own heat capacity, so the rate of cooling would differ. Using the same liquid is necessary, generally water. Their density also varies, so the heat capacity will vary along with it.

4. Flow rate of air(wind speed)
Manipulation of the above constant variable: if the wind speed is not constant then the rate of un-energized air molecules occurrence would not be constant. For this, there is no external wind used and the air is at rest.

5. The total duration of time:
this variable is the a constant, so that we can compare the data over a fixed duration of time and equally. So a constant time is taken.

Materials/Apparatus

In my experiment I will be using the following materials and apparatus:

100ml of water of a certain high temperature(less than b. pt. 100^oC)
Glass beaker, two different sizes
Glass measuring cylinder, two different sizes
Alcohol-in-glass thermometer
a stop watch
notepad and pencil( for noting the data collected)

Specifications:

Thermometer: Least count: 1^oC, Uncertainty value: 0.5^oC

Highest fixed point: 110^oC

Lowest fixed point: -10^oC

Beaker: Material: glass, Uncertainty value: 25ml

Least count: 50ml

Lowest fixed point: 50ml

Highest fixed point: 250ml

Measuring cylinder: glass, Uncertainty value: 2.5 ml

Least count: 5ml

L.F.P. : 50 ml

Highest fixed point: 500ml

Stop watch: Colour: yellow

Least count: 0.1seond

Procedure:

1) Then I decided to first start the experiment with the first container as the measuring cylinder.

2) A lab assistant provided me with the hot water, which I collected in the beaker for measurement of 100ml of water.

3) I poured it in the measuring cylinder and placed the alcohol-in-glass thermometer.

4) The alcohol showed a rise till a point of 80^oC.

5) Immediately I switched on the stop watch. For 5 minutes I noted the temperature drop every 30 seconds.

6) After 5 minutes of experiment I stopped the timer and threw the water. It had decreased and I noted all the changes.

7) Then I carried the same process for the other measuring cylinder, and the other beakers

8) For each container, I would repeat the steps 2-6.

Diagram

DATA PROCESSING

	OD= 41 53 = Height		55 mm = OD 360 mm = Height		88mm = OD 122mm = Height		AVERAGE
	Try1	Try2	Try1	Try2	Try1	Try2	1320.25 mm²	2375.83 mm²	6082.12 mm²
00:00	80	80	80	80	80	80	80	80	80
00:30	79	79	78	78	78	78	79	78	78
01:00	77.5	78	75.5	76	75	75	77.75	75.75	75
01:30	76	77	73	75	72	72	76.5	74	72
02:00	75	75.5	72	73.5	70	71	75.25	72.75	70.5
02:30	74	74	71	72	69.5	70	74	71.5	69.75
03:00	73	73.9	70	71	68	68.5	73.45	70.5	68.25
03:30	71.5	72	69	70	67	67	71.75	69.5	67
04:00	71	72	68	69	65.5	65.5	71.5	68.5	65.5
04:30	70	71	67	68	64.5	64	70.5	67.5	64.25
05:00	69	70	66	67	64	63	69.5	66.5	63.5
	Surface Area (mm²):	1320.25	Surface Area (mm²):	2375.83	Surface Area (mm²):	6082.12

From the above table and averages, we can construct a graph which looks like:

As per my graph, the lines with higher surface area have a greater fall in temperature, than the one with less surface area. Their decreasing almost linearly, however at one point the blue and green lines curves slightly, which shows some errors, occurred. However, their lines have ended approximately 3 degree difference.

Rate of cooling: final - initial temperature/ total time taken

1. For 6082.12 mm² the rate of cooling: (80 - 69.5)/5 min = 2.1 ^oC fall per minute

2. For 2375.83 mm² the rate of cooling: (80 - 66.5)/5 min = 2.7 ^oC fall per minute

3. For 1320.25 mm² the rate of cooling: (80 - 63.5)/5 min = 3.3 ^oC fall per minute

Conclusion

From the above observations and by recalling my hypothesis, it is clearly proven that my hypothesis is proven correct. My hypothesis states, if the base surface area of the container is increased, then the rate of cooling would be higher. As per my data, the container with 6082.12 mm² has the rate of cooling of 3.3 ^oC fall per minute whereas for surface area of 1320.25 mm² had the rate of cooling is 2.1 ^oC fall per minute. This proves that there is higher rate of cooling for a larger base than a lower surface are of the base.

Evaluation

The practical investigation, resulted with expected results, and they are quite accurate, however, at one point, there might have been some mistake, due to the fact that each of the average values have ended up to be different by 3 degrees approx. Due to uncertainty, some temperatures, might be approximate and this affected the results slightly. One drawback of the materials, were that one measuring cylinder was used and two beakers. Assuming beakers and the cylinder having same density, still have some varying results, because the base type of the measuring cylinder had some extra glass matter, (for a good base) but the beakers, did not have. This might have affected the rate of cooling. The initial temperatures of the water were not accurately 80 degrees, because the thermometer had a least count of 1 degree, not more. A more drawback is the human responding system, which is not accurate to milliseconds, affecting the results, nominally. Some of the errors, are uncontrollable, however some of them can be improved if I get to carry the investigation once again.

Please Leave Your Comments And Your Queries/Doubts In The Suggestion Box. Please Provide Some Suggestions About Other Topics Of Essay.

School curriculum provides everything that an average teenager should know about adult life? Do you agree with it?

2011-04-20T21:58:00.000+07:00

School is a place of knowledge. We learn several things from school. The knowledge and understanding we receive from school is numerous, and so it is correct when one says that school curriculum provides everything that an average teenager should know about adult life. I support this statement due to several reasons.

School curriculum provides us several subjects. Each subject is unique and has different types of occupations related to it. An average teenager would have enough information about each subject and respective fields. Then he can choose wisely his profession and also have a background about other subjects.

A student will learn to do several tasks i.e. multitasking at school. Adults really require this specific skill to balance their work, family, social life and finances. Within a school, teenagers are provided with several tasks like projects and essays all together, so this adds to the development of multitasking. This technique also aids in time management skills. This knowledge is not provided yet developed in teenagers due to the school curriculum.

Competition is another aspect a teenager learns within school boundaries and outside also. Tests, ranks and rewards make him compete more as adults always face competition.

A teenager can be totally independent in his work because he doesn’t get help from his parents when in school and teachers help only to a certain extent. This ensures the student uses his full potential to be what he wants to be.

My opponents might say that even after such a curriculum there are so many evils in society. Well for them, I can say that a bad man will be bad with or without school. School tries its best to avoid such happenings by punishments. To prevent those acts a school also provides information related to the harmful effects of evils in the society, but it is impossible to stop a person from committing a crime if that thought us in his mind.

My opponents may even say that so many talents are overlooked these days. It’s not just the school that is responsible for it. A school tries its level best to try and arrange as many extra curricula activities and competitions, so that more students are motivated and inspired to join. Teachers may even force the students but he himself should display his talent. The ones, who show out their talents, reveal their hidden talents and also become very courageous.

Thus I support that school curriculum provides enough scope for a student to learn and grow in such a way that he is prepared for adult life. After all, the curriculum was designed with lots of care and accuracy as per the students’ mental calibre.

Please Leave Your Comments And Your Queries/Doubts In The Suggestion Box. Please Provide Some Suggestions About Other Topics Of Essay.

Delights of Jogging

2011-03-22T14:31:00.000+07:00

Delight of Jogging

The Physical Benefits: Jogging is one of the pleasures of life. According to Danish research on 20,000 people, premature death occurs far less for joggers. Jogging increases blood circulation leading to better heart conditions. It also aids the digestive system and prevents any disorders. A slow easy jog can decrease your weight without ever actually getting exhausted or breathless.

Mental benefits: At first jogging is the pain in neck however this gradually turns out to be a part of life. It is like a connection between your brain and your body. Jogging however is like shark, if it doesn’t move forward it is dead. Jogging will make your mind fresh and also is a great solution for passing time.

Different stages of the process: Starters may face a little unpleasantness. You might get a red face along with sweat and tiredness. Eventually this will make you feel very interesting. A first 2 minutes may exhaust you but a continuous jog will eventually increase your limits to 20 minutes or even more. You will then have rosy instead of a red face along with extra stamina and energy within you.

SO MEMBERS LOVE WHAT YOU ARE DOING AND LOVE JOGGING SPECIALLY UNDER A WIDE OPEN SKY.

And Remember a jog a day keeps the fatigue away.

BADMINTON

2011-03-22T14:24:00.003+07:00

Introduction

I have decided design a training program to improve the components of fitness required in the game of Badminton one of the most famous games in the world today. It is the most popular sport in many regions. The program is intended to improve skills of badminton as well as the components of fitness that are needed if you want to be famous badminton player.

The Components of fitness:

1. Muscular Endurance: Strength and endurance together combine to be muscular endurance - The ability to execute several repetitions against a given opposition for a long period of time. A player in badminton repeatedly uses his muscular movements for moving, hitting shuttle etc. the most important muscles for player in badminton are legs and hand muscles, which continuously move for the various movements in the game.

2. Strength/Power: Power enables, athlete, or a player to apply the largest amount of their maximal strength in the shortest period of time. Badminton involves faster movements and higher power outputs than are found in maximal strength exercises. Player might not be able to apply large amounts of strength, if they are unable to apply their strength rapidly. This is why power is one of the important components of fitness.

3. Cardiorespiratory: Cardiorespiratory fitness is the ability of the circulatory and respiratory systems to supply oxygen to all muscles especially skeletal muscles during sustained physical activity. We all know that badminton is a fast and long game (proper game), which requires a lot of vigorous exercises. Oxygen and respiration are highly required for the game and so, I think it is one of the basic requirements of badminton players.

Training Program:

Muscular Endurance: muscles tear and wear is one of the main problems for each player. So we need to train our muscles to withstand more weights, and efforts, and movements.

Power: the power programmes should include larger force applied at higher speeds and for longer distances.

Cardiorespiratory: another name for aerobics, need exercises, which will increase the blood circulation and breathing rate and controls.

Circuits are great programmes for trainings as they can be repeated for long time without stopping and as per required:

Description

1. Jogging on spot: it is as easy as it sounds, we jog on spots

2. Bow and arrow stretching for arms: when one arm opens in the chest level, the other hand closes(bends towards chest)

3. Both wrist rotations in both direction: we rotate our wrists right and left directions

4. Head Rotation in both direction: we rotate our head our right and left direction in a circular path

5. Squats: we bend our knees, sit on our toes, and bend our body like we are sitting

6. sit-ups on a rod and lift weights: the player anchors the knee back on a long rod and balance our whole body, and hold dumbbells and do regular sit-ups (training, hand muscles and stomach for movements)

7. dance on spot: do any dance which includes hand and leg movements

8. Do breathing exercises like in Yoga: take air in with one nostril and release with other. Hold breath for few seconds before breathing in or out.

9. Power Jumps: jump high with as much force possible with our legs

10. Kick front and back: kick front and back with both legs

11. Move right and left in the same place: shift right and left on a line, with legs wide apart as the stance in badminton.

12. Freestyle hand movements: hold our elbow with our finger and move thee complete hands front rotation and back.

Each of the steps should be done for 1- 1.5 minutes, but each exercise should be given equal timing to train ourselves equally. And less than 1 minute won’t give high training for each exercise.

Evaluation

After making the steps, I tried them. The hardest of them was the sit-ups on rod with weight. We need to be trained properly to do sit-ups, before we can do that, as guided by the gym instructor of my apartment, Taman Rasuna. The yoga moves were easy but we need to hold the breath for long in order to train quickly. The first 4-5 steps are for warming up of body and the rest for proper training. The rotational hand movements, and muscular movements, improved my muscular ability to hit harder shots, the jogging and moving right to left also made my movement in the game faster. My reflex also increased due to active brain and body. I had tried the exercises one circuit each day for a week and the results were good, except for the sit-ups.

Economics Essay- Rising global unemployment

2011-01-25T16:40:00.000+07:00

The population of an economy is divided into 2 categories, the economically active and the economically inactive. The economically active population (labour force) or working population refers to the population that is willing and able to work, including those who are actively engaged in the production of goods and services (employed) and those who are unemployed. Unemployed refers to people of the economy who are willing to work, but are not able to find suitable paid employment.

As said by the PARIS organization, on September 16^th 2009, “Unemployment in the industrialized world will hit its highest level since World War II next year, surpassing the current peak, as the global economy looks set for only a timid recovery in 2010, an international organization said in a report Wednesday.” As said by this news report, Global unemployment has been skyrocketing the past few months and is expected to attain its peak in the coming year 2010. The LFB-Forex states that “Over the last quarter a rather grim picture from the global labor market revealed itself, as the unemployment rate rose to multi-year highs in most economies.” in an article posted on July 6^th 2009. Probably the most important headline was that the unemployment rate moving to 9.5% in the U.S., the highest level since 1983. The same thing happened around the globe; the unemployment rate surged to record high values. Below is a graph that explains the above statement.

As the graph above shows, during years 2002-2003, unemployment rate is moving at a steady and slightly decreasing rate for countries such as U.S.A, Japan, Spain and more. During years 2007 onwards, unemployment rate begins to escalate to great heights and finally reached its peak so far in the year 2010.

Among all these countries, Asian countries are highest affected by unemployment rates due to lag in technology and some resources. Among these highly affected countries, is Indonesia. Below is a table which consists of the different percentage changes of unemployment rates in Indonesia for years 2003 through 2010:-

Year	Unemployment rate	Rank	Percent Change	Date of Information
2003	10.60 %	92		2002 est.
2004	8.70 %	111	-17.92 %	2003 est.
2005	9.20 %	82	5.75 %	2004 est.
2006	11.80 %	121	28.26 %	2005 est.
2007	12.50 %	133	5.93 %	2006 est.
2008	9.10 %	115	-27.20 %	2007 est.
2009	8.40 %	115	-7.69 %	2008 est.
2010	7.70 %	81	-8.33 %	2009 est.

http://www.indexmundi.com/indonesia/unemployment_rate.html

An article posted in the Jakarta Post on September 26^th 2006 states that “The unemployment rate has reached an alarming level since it has risen to double digits. Despite its fluctuating drops, the unemployment rate has remained high. According to National Statistics Bureau data, as of June 30, 2006, the unemployment rate stood at 10.6 percent, or 11.6 million of the 106 million-person workforces, a 2 percent increase on the 9.5 million of the end of 2005. Under-unemployment, or those working less than 35 hours a week, has exceeded 43 million.”

More than 10,5 million Indonesians are seeking work. Neither under-qualification for labor nor discouragement is to blame for this high unemployment, but rather the low productive investment rate and unhealthy investment climate. There is a moral and political imperative for the Indonesian government to get the unemployed back to work and to create new employment for an almost two million new labor force entering the economy sectors annually.

To understand the patterns of unemployment in Indonesia, we must first understand the labor forces of Indonesia. Below is a graph which shows the total labor force in Indonesia over the years 2003 through 2010:-

http://www.indexmundi.com/indonesia/labor_force.html

As the graph depicts, the labor force of Indonesia is at its highest this year and has matched its value along with 2005. Among these labor forces lie underqualified, unskilled labor forces. This may be a leading cause to the Unemployment in Indonesia. Most of the unemployed in Indonesia are young and inexperienced, still live with their parents, and have at least 12 years of education. Meanwhile, the poor who are not working, and to a certain extent the non-poor who are low educated and unemployed, tend to become discouraged.

This is one of the causes of Seasonal and Frictional Unemployment in Indonesia, and actual discouraged labor composes only a quarter of half unemployment or 18.3% of total open and half unemployment.

While unskilled labor forces contribute to the rise in unemployment in Indonesia, Many authors have accused the low economic growth rather than the unsatisfying labor quality as the key contributor to Indonesia’s unemployment. After the financial crisis of 1997- 1998 Indonesia’s economy has improved its GDP’s growth from 0.79% in 1999 to 5.6% in 2005. This data is expressed in the graph below:-

http://www.indexmundi.com/indonesia/gdp_real_growth_rate.html

Nevertheless, this positive development seems not to have a real impact in reducing the unemployment rate. The unemployment rate expands unrestrictedly with a 5.8% yearly average growth rate. The important essential factors that needs attention is the creation of better climate for investment. According to Kuncoro et al (2005) to start a new business in Indonesia, a company has to spend 180 working days to go through the 12 steps required for obtaining local permits. This drawback may lead to rise in unemployment in Indonesia.

ccording to macroeconomics, the Pattern of unemployment in Indonesia is well described as cyclic unemployment. This is because the Asian recession experienced in 1997-1998 lead to a downfall of the rupiah currency, which lead to a lower amount of spending, thus inevitably lowering output, production, productivity and finally employment. This condition is described as cyclic unemployment. There are a few measures to overcome cyclic unemployment namely:-

Genetically modified foods in our daily lives

2011-01-23T19:29:00.000+07:00

Introduction

Food is any substance or materials eaten or drunk to provide nutritional support for the body or for pleasure. Our everyday meal contains so many kinds of foods, and we don’t know half of their origins, or contents. Many foods today are genetically modified or altered to make it tastier, or long lasting. These foods are not always healthy, so we should think before eating them. Let us see what they are.

What are genetically-modified foods?
The term GM food or GMOs (genetically-modified organisms) are generally used for crops or organism that are engineered or created for human or animal consumptions. GM organisms are created in laboratory through biotechnologists. Generally they are used to make the foods crops more resistant to pests or having more flavour or appearance. Traditionally, modifications were done through breeding, but recently scientists are using genetic engineering to create exact specifications of what they want. For example, geneticists of plants often isolate a gene responsible aimed at drought tolerance and add that gene into another plant. The genes used are not only from plants, but also from other sources also. Bacillus thuringiensis, a natural bacterium, produces crystal proteins lethal to insect larvae. These genes have been transferred into corn, enabling the corn to produce its own pesticides against insects such as the European corn borer.
The genetic creating involves few stages:

1. Obtaining a copy of the gene required, where the scientists make a copy of the gene from its mRNA and then synthesis the gene artificially

2. Put the gene into a vector (carrier), which is introduced into a host cell.

3. Then the host cell is allowed to duplicate its DNA.

For plant modifications, viruses are used as carriers, in the plant cells, or even using guns, where the bullet made of gold or tungsten is coated with the required DNA onto the surface and shot using special guns. Vectors such as Agrobacterium are used which are bacteria which enter a wounded plant. These carry the DNA which later leaves the bacteria and enter the plant DNA, so the plant grows accordingly.
Advantages:
So many varieties of plant crops and animal products which have made our life easy are made like:

1. Herbicide-resistant crops: crops which are resistant to harmful herbs themselves are created like, herbicide resistant corn, wheat, sugar beet and oilseed rape.

2. Pest-resistant crops: crops can be made pest-resistant through special genes, so that the farmers don’t have to spray harmful pesticides which harm the soil also. Few experiments were done on potatoes, tomatoes and alfalfa.

3. Disease and weather resistant: Many diseases affect the plant and temperature also affects the plant growth (enzymes) so engineers have modified crops to make them resistant to it.

4. Drought tolerance/salinity tolerance: drought and salt water are two common environments today, so engineers have made plants tolerant to them.

5. Nutrition: Engineers have modified general foods so that they contain extra nutrition so that, the people who eat such foods as their main meal, would get all the nutrition.

6. Pharmaceuticals: special vaccines and medicines are being produced by crops, and animal products. Many proteins and hormones are also produced using such methods, like transgenic sheep milk contain antitrypsin.

Disadvantages
The disadvantages of GM foods are:

They may develop different and harmful properties.
The farmers have to continuously produce the specific crop for long time for preservations of the specie.
GM foods might change the microbial flora of the soil often causing degradation of essential microorganisms on soil.
These foods, might even affect our or any animal’s DNA who consumes it.
If in case food were antibiotic resistant, then their affects might enter the person consuming it also.
Insects can develop resistant mechanism as they feed on such GM crops.
Other organisms in the same medium might be affected also.
Few of these important foods, can carry toxic materials also, creating human illness.
Few consumer allergic to certain foods, might be affected some other GM foods which have traces of these foods. Few GM foods also can cause severe chemical reactions harmful to the body. In Brazil, individuals allergic to Brazil nuts were also allergic to the new GM soybean.

The table below:

Provides us with information of how many harmful substances were found in many GM foods.

Factors Affecting Manufacture of GM foods

Economic concerns

GM foods are costly, and especially when a new crop is developed, the cost of seeds goes rises and so farmers are not able to buy them easily. Bringing a GM food to market is a long and expensive process, and agri-biotech companies mainly wish to ensure a profitable return on their investment. These foods are expensive and many people cannot afford to buy them causing less demand and so less supply and production of such foods. Transgenic sheep milk costs about £ 50000 per mg which is pure 99.99%.

Ethical concerns

Genetically modified foods, are made by violating natural chain of food habits and life. We alter life according to our needs which is not ethical. There are Objections to consuming animal genes in plants and vice versa and also stress for animals, as they alter their DNA and life style and complete life is changed. Intrinsic concerns base on how people view their life, nature, religion, personal emotions and values. Few people believe that they have a feeling that mixing genes is like playing god and human beings should not intervene in God’s realm.

Environmental Concerns

GM foods cause unintended effects on the other organism for example, pollen from B.t. corn caused high mortality rates in monarch butterfly caterpillars as their seeds flew onto milkweed plants which these butterflies ate. These types of foods have however decreased the use of pesticides and herbicides so the environment and the soil are cleaner and less polluted. Gene transfer often to unintended species creating another change in their ecology.

Conclusion

Genetically modified foods have the power to save hunger problems, as less food is wasted and more are produced. Environment is cleaner and safer for all organisms for we have to spray fewer amounts of pesticides and herbicides. As the food grows for long time, the cost would decrease so more people can buy it by then. However there are many risks to our health also which we should consider and try to avoid. This technology however is one of the jewels of 21^st century and should be kept improving for better and safer foods for us.

Importance of electrolysis in our daily lives

2011-01-22T12:54:00.003+07:00

INTRODUCTION
In 1800, two Englishmen, William Nicholson and Anthony Carlisle, used an electric current to decompose water into its element, hydrogen and oxygen. This is an example of electrolysis. Electrolysis is the process of using electricity to break down or decompose a compound. It has a few main components – a battery, electrodes and an electrolyte. There are many applications of electrolysis.

Electroplating is one of the main areas where electrolysis is implemented.

Electroplating
It is the coating of one metal over the other which is called electroplating. It is done for few reasons to benefit us:

1. Resistance to corrosion and increased life span
2. Provision of insulation
3. Better appearance for e.g. chrome, nickel or silver can produce a mirror like finish

Resistance to corrosion and increased life span: A coat of one less valuable metal on a more valuable metal can be very beneficial. For example if zinc is electroplated on iron then it would protect iron from getting corroded and would ensure proper usage.

Provision of insulation: Insulating materials can be electroplated for safety of living organisms. Plastic for example can be electroplated on copper or aluminum for protection from shocks.

Better appearance: this one of the most common method used for everyday life coating. Electroplating of silver, chrome or nickel protects the base metal from corrosion, or scratches as well as provides a shiny attractive appearance for decorations or jewelry.

Electrotyping
This is a much of a decorative or labelling where a wax figure is made of desired shape and coated with carbon and used as an electrode which can deposit metals forming a solid plate made of a thin sheet of pure metal e.g., copper metal.

Electrolytic purification
In Today’s age, there is high demand for very pure metals. Electrolysis can be used to purify metals, such as purification of copper. A pure bar of cathode attached to the cathode can have deposits of that metal from the impure metal electrode from the anode.

Electro-repairing
This is a techniques used for repairing of broken machinery. The whole surface of the broken/damaged object or component is covered with wax except where the repair is needed and is made the cathode and dipped in an electrolysis bath. The metals deposits on the dent or the part open part. After enough metal is deposited, by further machinery it can provide the exact shape wanted.

Electric Cell
One of the most common used every day object, the battery cell, uses the electrolysis for voltage difference. It essentially reverses electrolysis. It is made by placing two different metals in contact with an electrolyte. The metals act as the electrodes for a simple cell. The farther away the two metals in the reactivity series, the higher voltage and current is produced.

Water Electrolysis
The water is one of the most common and the oldest technique discovered by scientist. Today it is used in many places. Water electrolysis is helping for a safer poultry industry. It is also used for collecting oxygen and hydrogen separately for their specific purposes, like for use of oxygen in the oxygen tanks which also contains argon. Hydrogen can be used as fuel or it is used in massive quantities in the petroleum and chemical industries.

Hair removal

A minor but very useful method of looking good in society is electrolysis hair removal. Electrolysis hair removal is the only method approved by the FDA for without requiring multiple sessions, permanent hair removal isn't 100% guaranteed for everyone.

A minor use is in the capacitors which stores electricity and provides it when switching on something.

Additional Benefits/Uses of Electrolysis

Disadvantages Of Electrolysis

Electroplating works on a molecular level, so it may forms an extremely thin layer, so either we use only one thin layer or provide multiple coating to it. When ions of the superior metal adhere to the base metal it is often uneven or bumpy which creates a problem. Even though the coating is good, the coating can be easily cracked or is brittle, especially true with chrome. Plating companies produce large amounts of pollution which creates other troubles like diseases are created.

In hair removal should the needle enter and an electric charge is discharged into the skin, you could get a scar.

In machineries using electrolysis it is difficult to coat internal diameters and there are dry torque problems. It consumes space in the shop or factory and also might generate waste chemicals which can be harmful to the environment and also may contain the valuable metal.

Environmental Issues

The industries using electrolysis release large amounts of effluents as wastes. Authorities regulate a particular amount of waste that should be regulated not more than that. There are very few metal finishing plants from which the rinse waters can be discharged directly to the sewers as the contaminant concentrations are outside the limits set by local authorities. With the majority of instillations, therefore, effluent treatment is necessary.

In effluent treatment the usual practice is to separate the acidic discharges, together with those containing nickel or chromium from alkaline and cyanide discharges which may contain metals such as zinc, cadmium or copper.

Ethical Issues

The companies and industries should always try to reduce pollution by following few methods like:

o Keeping the plating areas clean and preventing foreign materials from entering the site.

o A part that falls off the rack into a bath should be removed quickly to reduce contamination.

o Firms should avoid using broken or cracked racks

o Proper control of bath operating parameters can result in more consistent work piece quality

o Facilities should perform daily or weekly tests and analysis for proper inspection.

Social issues

Due to electrolysis or electroplating, people can be affected in many ways. Pollution can cause any disease to any one on a general basis, however due to electroplating there can be occupational asthma. People living around those people can get affected too spreading the disease to others and the society. However the electrochemical or electrolysis field has increased the job opportunities for the people and thus developing the country.

Conclusion

Electrolysis has a major use in our day to day life, because it provides several products as well as makes us looks good and satisfied. It provides a fuel, as in hydrogen and gives us extra life, as for the oxygen. It is true that there are disadvantages for electrolysis, like giving us scars, creating pollution or increases the time required for making one product however it has so many good effects too, like providing permanent hair loss to most people as well as give a lustrous look to a dull metal or even provide electricity in emergency or mobile devices. I think without electrolysis our life would be incomplete.

BIBLIOGRAPHY

1. "Applications of Electrolysis." TutorVista.com-Over 5,029,000 Live Tutoring Sessions Served ! Web. 15 Aug. 2010. <http://www.tutorvista.com/content/chemistry/chemistry-iii/redox-reactions/electrolysis-applications.php>.

2. Beach,, Emily. "Types of Electroplating." EHow | How To Do Just About Everything! | How To Videos & Articles. 7 Oct. 2009. Web. 18 Aug. 2010. <http://www.ehow.com/about_5502274_types-electroplating.html>.

3. "Benefits of Electrolysis - Removing Hair (UK)." Eliminating Unsightly Hair at Removing Hair (UK). Web. 18 Aug. 2010. <http://www.removinghair.co.uk/BenefitsOfElectrolysis.html>.

4. "Electrolysis: Commercial Applications of Electrolysis — Infoplease.com." Infoplease: Encyclopedia, Almanac, Atlas, Biographies, Dictionary, Thesaurus. Free Online Reference, Research & Homework Help. — Infoplease.com. Web. 17 Aug. 2010. <http://www.infoplease.com/ce6/sci/A0857942.html>.

5. "ELECTROPLATING SERVICES." Advanced Plating & Polishing Services Ltd. Web. 17 Aug. 2010. <http://www.plating.co.nz/plating.asp>.

6. Hewis, John. "Capacitors." Welcome to the Electronics Club. Web. 18 Aug. 2010. <http://www.kpsec.freeuk.com/components/capac.htm>.

7. Holiday, Jim. "ADVANTAGES AND DISADVANTAGES OF NEW ELECTROPLATING TECHNOLOGIES: CORPUS CHRIST1 ARMY DEPOT." Web. 18 Aug. 2010. <http://www.p2pays.org/ref/19/18753.pdf>.

8. Litherland,, Neal. "The Disadvantages of Electroplating | EHow.com." EHow | How To Do Just About Everything! | How To Videos & Articles. 1 June 2010. Web. 17 Aug. 2010. <http://www.ehow.com/list_6577444_disadvantages-electroplating.html>.

9. "Occupational Asthma Due to Chrome and Nickel Electroplating. -- Bright Et Al. 52 (1): 28 -- Thorax." Thorax - BMJ Journals. Web. 18 Aug. 2010. <http://thorax.bmj.com/content/52/1/28?related-urls=yes&legid=thoraxjnl;52/1/28>.

10. "Pollution Prevention in the Plating Process." Pollution Prevention (P2) Pays - N.C. Division of Pollution Prevention and Environmental Assistance. Web. 18 Aug. 2010. <http://www.p2pays.org/ref/03/02454/plating.htm>.

11. Tan, Yin Toon., Ling Chen Kwong, John Sadler, and Emily Clare. "Chapter 15: Electrolysis." GCE 'O' Level Chemistry Matters. Singapore: Marshall Cavendish Education, 2007. Print.

12. "Water Electrolysis for a Safer Poultry Industry." Food Production Daily Food Processing & Packaging Materials (food Equipment, Processing Machinery, Packaging Materials for Food Processors). 25 June 2004. Web. 17 Aug. 2010. <http://www.foodproductiondaily.com/Quality-Safety/Water-electrolysis-for-a-safer-poultry-industry>.

Please Leave Your Comments And Your Queries/Doubts In The Suggestion Box. Please Provide Some Suggestions About Other Topics Of Essay. Follow my blog to get a lot of information and help,

Physics Practical Report: How can the distance of an object from a specific convex lens affect its image formed on the other end of the lens?

2011-01-20T23:45:00.000+07:00

Problem to be investigated:

How can the distance of an object from a specific convex lens affect its image formed on the other end of the lens?

Back ground on the topic to be investigated:

Convex lenses are of different thickness, density and curvature however all the convex lenses have few common properties:

Any lens always a fixed focal point, thickness, density and a centre of curvature.

When an object is placed in front of a lens, the lights rays travelling from the object fall on the lens and get refracted. The refracted converging rays produce an image at a point where all the rays meet or intersect. For demonstrating this as a diagram, two rays are taken and constructed for showing the point of intersection. In general objects at different distances from the lens would create different sized images.

Hypothesis – An object is placed on one side of a convex lens can give an image of different magnification or size with change in the placement of object. So, if the object is placed farther away from a lens the image formed would be smaller and nearer to the lens on the other side. The image formed will also be inverted.

Variables

1) Independent – Distance between the object and the lens (u).

i) Dependent –
a) Distance between the lens and the image (v)
b) Size of the image

2) Constants –

i) Convex Lens, Its:
a) density
b) thickness
c) refractive index

ii) Height of the lens and the object

iii) The unit of measurement

Manipulation of Variables

The distance of object from lens can be altered by hand movement. As the light passes the lens it gets refracted to a different position and the so the distance of the image changes as well as the size of the image.

The convex lens used remains constant so its density, thickness and refractive index stay constant. The lens is placed on a stand and a candle of some height is placed in front of it so their height also remains constant. Finally the unit measured in should be kept constant or there might be mistake.

Material required

ü Wax Candle

ü Matchstick (for lighting the candle)

ü Wooden block(if candle height is too small)

ü Lens Holder

ü Convex lens

ü Screen

ü Meter Rule

Method

1) Firstly all the apparatus are collected with a proper lens and a proper thickness (not too thick nor too thin)

2) Now the experiment is set up as per figure 1.1. The lens is in the lens holder, candle on the wooden block and a screen to capture the image.

3) After, all three are in place; the candle is lighted and placed at a measured distance from the lens. The different (u) value length taken will be:

i) 25

ii) 30

iii) 35

iv) 40

v) 45

vi) 50

vii) 55

viii) 60

4) Now the image formed is observed. The screen is shifted up and down to get the clearest image of the candle light.

5) Then we measure this distance ‘v’ and note it.

6) Now the steps 1-5 are repeated for the same ‘u’ values two more times.

7) Next all the data is recorded in a table which looks like as follows:

Calculated data with the focal length and magnification of the image

Focal Length = (uv)/ (u+v)

Magnification = v/u

Safety Measure:

1. The ruler used should not be bent or there can be mistake in the reading.

2. The Lens should be handled carefully or it might break.

3. The flame used should be controlled and small and playing with the match sticks or lighters shouldn’t be implemented.

Data Processing

(all units to be measured are in cm except magnification)

Raw Data:

		Try 1	Try 2	Try 3
Sl. No.	object distance (u)	image distance (v)	image distance (v)	image distance (v)	Average
1	25	64.3	64.3	64.3	64.30
2	30	46.5	46.5	46.4	46.47
3	35	38.5	38.6	38.5	38.53
4	40	33.7	33.8	33.5	33.67
5	45	31.4	31.5	31.5	31.47
6	50	29.7	29.6	29.9	29.73
7	55	28.5	28.5	28.6	28.53
8	60	27.7	27.5	27.6	27.60

Thus the analysed table is as follows:

Sl. No.	object distance (u)	image distance (v)	Magnification = v/u	Focal Length = (uv)/ u+v
1	25	64.30	2.572	18.00111982
2	30	46.47	1.548888889	18.23016565
3	35	38.53	1.100952381	18.34088849
4	40	33.67	0.841666667	18.28054299
5	45	31.47	0.699259259	18.51787271
6	50	29.73	0.594666667	18.64548495
7	55	28.53	0.518787879	18.78691141
8	60	27.60	0.46	18.90410959

A graph can help illustrate the data collected more effectively as follows:

A graph on Object distance vs. Image dista

Please use a spreadsheet, cant upload graphs

A graph on Object distance vs. Magnification:

Please use a spreadsheet, cant upload graphs

Analysis

These two graphs and tables demonstrate that with an increase in the object distance from the lens, the size of the image decreases as well as the distance of the image formed from the lens clearly. Both the lines are progressing in a negative slope signifying that the further away the object is from lens the smaller and nearer the object will form.

Conclusion:

The investigation on how can the distance of an object from a specific convex lens affect its image formed on the other end of the lens had fruitful results. The hypothesis stated if the object is placed farther away from a lens the image formed would be smaller and nearer to the lens on the other side. According the planning and manipulation of variables, the experiment had successful results after all. The hypothesis has been proved and illustrated even on graphs. It was also observed that when the candle grew shorter and the object level dropped, its image level increases and also the image formed were always inverted.

Evaluation

The investigation conducted has been a success. It has proved my hypothesis correctly. The variables were correctly controlled however the height of the wax candle had decreased since it was burning for long time. The readings were much or less correct but weren’t precise. This could have been the problem because of small parallax errors or maybe because the wooden ruler wasn’t properly straight. Another reason why the readings weren’t correct was because it is not possible to place the screen exactly at the perfect meeting position of the rays. So the next time I can keep these small things in mind and get a better result.

Suggestions

Few suggestions to the methods could have been:

1) Candle flame could have been replaced with a torchlight which would remain a stationary beam of light at point along with a stronger light beam.

2) The ruler used should have been maintained as a straight rigid bar. (Not bent).

P.S. : Please leave a comment or tell whether it was useful, interesting or not,TY