Particles A and B, of masses 2 kg and
Mkg respectively, are attached to
the ends of a light inextensible
string which passes over a smooth
fixed pulley. B is held at rest on the
horizontal floor and A hangs in
equilibrium.

B is released and each particle starts to
move vertically. A hits the floor 1.5s
after B is released.
The speed of each particle when A hits
the floor is 3.5 ms.
(1) For the motion while A is moving
downwards, find the acceleration of A
and the tension in the string.
li) Find the value of M.