Here's the question; "In an orienteering competition, a competitor moves in a straight line past three checkpoints. P, Q and R, where PQ=2.4km and QR=11.5km. The competitor is modelled as a particle moving with constant acceleration. She takes 1 hour from P to Q and 1.5 hours to travel from Q to R. Find:
a) the acceleration of the competitor
b) her speed at the instant she passes P.
Another question "Two particles P and Q have masses 0.5kg and 0.4kg respectively. The particles are attached to the ends of a light inextensible string. The string passes over a small smooth pulley which is fixed above a horizontal floor. Both particles are held, with string taut, at a height of 2m above the floor. The particles are released from rest and in subsequent ,onion Q does not reach the pulley. When particles have been moving for 0.2s, the string breaks. Find the further time elapses until Q hits the floor."