(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

[PLAIN]http://img208.imageshack.us/img208/9987/forcediagram.png [Broken]

In the figure above, two small objects (magnets for instance) of the same mass exert forces on each other of a magnitude F. When object A is subjected to an external force of 3.6x10^-2 N, A accelerates at 1.6 m/s/s and B accelerates at 2.1 m/s/s as shown. Find F. Neglect other forces, assume accelerations are parallel.

2. Relevant equations

F=ma

ƩF = ƩmƩa

3. The attempt at a solution

I'm not sure if the solution i got is entirely correct but this is it

ƩF(A) = 3.6x10^-12

ƩF(B) = (3.6x10^-2) + F

I got this because B is accelerating faster which means the force on B must be greater if the masses are equal.

Using this, I found the mass of A, by F = ma

3.6x10^-2 = m(1.6)

m = .0225 kg, so A and B are .0225 kg

To find F, I substitute the mass into F = ma for F(b)

So

(3.6x10^-2)+ F = .0225*2.1

F = 1.13x10^-2 N

Is that correct?

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# Homework Help: Newton's Law question, Not sure if right

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