Two particles A and B have masses 0.12 kg and 0.38 kg respectively. The particles are attached to the ends of a light inextensible string which passes over a fixed smooth pulley. A is held at rest with the string taut and both straight parts of the string vertical. A and B are each at a height of 0.65 m above horizontal ground (see diagram). A is released and B moves downwards. Find

1. the acceleration of B while it is moving downwards,
2. the speed with which B reaches the ground and the time taken for it to reach the ground.

B remains on the ground while A continues to move with the string slack, without reaching the pulley. The string remains slack until A is at a height of 1.3 m above the ground for a second time. At this instant A has been in motion for a total time of T s.

3. Find the value of T and sketch the velocity-time graph for A for the first T s of its motion.
4. Find the total distance travelled by A in the first T s of its motion.