Particle Mechanics exercises. Please help.

[hyorin.choi]

Homework Statement

Two particles A and B, of masses 2m kg and m kg respectively, are connected by a light inextensible string which passes over a fixed smooth pulley. The system is released from rest, with both portions of the string vertical and taut, while A and B are at the same height. Find the magnitude of the acceleration of the particles and the tension in the string.
The string breaks when the speed of each particle is u m/s. Find, in terms of u, the difference in height between the particles A and B,
a. when the string breaks.
b. when B reaches it s highest point, assuming that A has not reach the ground and B has not reached the pulley.

 

[BvU]

Hello HC, welcome to PF !

So far for the problem statement. Interesting.

Now for the rest of the template. The guidelines require an effort on your part to come to a solution. That also helps us to provide more useful assistance: you don't need the answer, you need the exercise !

Homework Equations

The Attempt at a Solution