Physics, Chemistry, Maths Forum

Question About Math In Chemistry.

Wed, 14 Jan 2015 00:12:07 GMT

by Petek Savaş.

Hi community,

I have an exam tomorrow morning and I need answers of 3rd and 5th questions. Thanks.

Physics-rotation

Tue, 13 Jan 2015 16:48:16 GMT

by Kavitha G.

A uniform rod of mass m and length 2l lies on smooth horizontal surface. A particle of same mass m is connected to string of length l whose other end is connected to rod. Initially, string is taut and both string and rod lie in the same horizontal plane with angle 90⁰ between them. If particle is given initial velocity v_o perpendicular to string, then just after giving velocity v₀ to particle, find (a) linear acceleration of center of mass of rod, (b) angular acceleration of rod (c)tension in string (d) angular velocity of rod.

The answer for part (c) : Tension = mv₀²/5l

Kindly explain.

Re: Kinematics

Mon, 27 Oct 2014 06:58:55 GMT

by Frida. Niggard.

In physics the term "deceleration" isn't really used. If an object that is moving in a straight line is speeding up, then it is experiencing a positive acceleration. And if it is slowing down, then it is still accelerating but now with a negative value.

Newton's equation F=ma (Force = mass x acceleration) must always be true. And we know that it takes a force to change the speed or direction of any object. So, if an object is speeding up, slowing down, or changing direction, and since the mass is a constant value, then to keep the equation balanced the value of acceleration simply can not be 0.

So, if you were to move at a constant speed "in a straight line" then you would not be accelerating. But... One quick example of moving at a constant speed where you would be experiencing acceleration is to ride a Merry-Go-Round.

Re: Kinematics

Tue, 02 Sep 2014 14:13:30 GMT

by Srinath Murthy.

Deceleration is negative acceleration. Circular motion is the typical example where speed can be constant without acceleration (or negative deceleration) being zero.

Re: Momentum

Fri, 20 Jun 2014 10:43:27 GMT

by Rajat Rao.

Resolve velocity of B along and perpendicular to AB. It is u/2 and u*(sqrt(3))/2.

For direction perpendicular to AB, apply conservation of linear momentum to get velocity of A = u/4. Apply conservation of angular momentum to get velocity of A = -u/4. So, velocity of A perpendicular to AB = 0.

For direction along AB, apply conservation of linear momentum to get velocity of A = u*(sqrt(3))/4.

Which is the required answer.

Momentum

Thu, 19 Jun 2014 17:48:52 GMT

by Kavitha G.

Two particles A and B each of mass m are attached by light inextensible string of length 2l. (Initially string is not taut.) The whole system lies on smooth horizontal table with B initially at a distance l from A. The particle at end B is projected across the table with speed u perpendicular to AB. Velocity of particle A, just after the string is taut, is:

Ans: u(root{3}) / 4

Kindly explain.

Organic Chemistry, Alkyl Halides

Thu, 01 May 2014 23:45:05 GMT

by Tetrahedron G.

What is/are the product when this reacts with Lucas reagent?

What would be the product(s) if this alcohol reacts with Lucas reagent? Would Methyl shift happen ? I heard that in Groove's process, only primary and secondary alkyl chlorides are formed.

Kinematics

Tue, 28 Jan 2014 10:18:43 GMT

by ramakrishna masabattula.

Can a body decelerate while moving with constant speed? if so mention an example.

Re: gravitation

Tue, 14 Jan 2014 15:48:37 GMT

by Braj Arora.

Where m is the mass of the point mass.

Re: Thermodynamics

Fri, 13 Dec 2013 12:20:16 GMT

by Kavitha G.

W = - (integral)PdV [This is a question in chemistry]

So, U/w should be -3