Block P, of mass 2 kg, lies on a rough horizontal table. A light inextensible string connects P, over a smooth light pulley fixed at the edge of the table, to block Q, of mass 5 kg, which hangs freely. The coefficient of friction between P and the table is 0.25. The system is released from rest with the string taut, and Q descends, pulling P towards the pulley. Take g = 9.8 m/s2. Find the acceleration of the system, and the tension in the string, while both blocks are moving.
Figure (to be drawn): Diagram: block P on a rough horizontal table, connected by a string over a smooth pulley at the table edge to block Q, which hangs freely and descends when the system is released.
(Total for Question 19 is 4 marks)