Particles P and Q, of masses 0.6 kg and 0.4 kg respectively, are attached to the ends of a light inextensible string. The string passes over a small smooth pulley which is fixed at the top of a vertical cross-section of a triangular prism. The base of the prism is fixed on horizontal ground and each of the sloping sides is smooth. Each sloping side makes an angle θ with the ground, where \\sin θ = 0.8\\. Initially the particles are held at rest on the sloping sides, with the string taut (see diagram). The particles are released and move along lines of greatest slope.

1. Find the tension in the string and the acceleration of the particles while both are moving. [5]

The speed of P when it reaches the ground is 2 m s^-1. On reaching the ground P comes to rest and remains at rest. Q continues to move up the slope but does not reach the pulley.

2. Find the time taken from the instant that the particles are released until Q reaches its greatest height above the ground. [4]