9709 P41 - Nov 2013 - Q6
3944
Particles A and B, of masses 0.3 kg and 0.7 kg respectively, are attached to the ends of a light inextensible string. The string passes over a fixed smooth pulley. A is held at rest and B hangs freely, with both straight parts of the string vertical and both particles at a height of 0.52 m above the floor (see diagram). A is released and both particles start to move.
(i) Find the tension in the string.
When both particles are moving with speed 1.6 m s-1 the string breaks.
(ii) Find the time taken, from the instant that the string breaks, for A to reach the floor.
