5.
\includegraphics[max width=\textwidth, alt={}, center]{14759a7d-dbec-4d72-a722-c83043fb59c5-12_501_880_132_614} Two particles \(P\) and \(Q\) are attached to opposite ends of a light inextensible string which passes over a small smooth pulley at the top of a rough plane inclined at \(30 ^ { \circ }\) to the horizontal. \(P\) has mass 0.2 kg and is held at rest on the plane. \(Q\) has mass 0.2 kg and hangs freely. The string is taut (see diagram). The coefficient of friction between \(P\) and the plane is 0.4 . The particle \(P\) is released.

1. State the tension in the string before \(P\) is released, and find the tension in the string after \(P\) is released.
   \(Q\) strikes the floor and remains at rest. \(P\) continues to move up the plane for a further distance of 0.8 m before it comes to rest. \(P\) does not reach the pulley.
2. Find the speed of the particles immediately before \(Q\) strikes the floor.
3. Calculate the magnitude of the contact force exerted on \(P\) by the plane while \(P\) is in motion. End of Examination Extra Answer Space