Any help would be great thanks
A light inextensible string passes over a fixed smooth pulley. Particles A and B, of o.o3kg and o.o5kg respectively, are attached to the ends of the string. The system is held at rest with A and B at the same horizontal level and the string taut. The two parts of the string not in contact with the pulley are vertical. The system is released at time t=0, where t is measured in seconds, the particle B moves downwards for 2s before it hits the floor. The string then becomes slack and B remains a rest. Neglecting air resistance, show that the string becomes taut again when t=3.