Two particles P P\,P and QQQ, of mass 4 kg and 6 kg respectively, are joined by a light horizontal rod. The particles are initially at rest when a constant force F F\,F of magnitude 30 N is applied to QQQ, as shown in the diagram. The force is applied for 5 s. During the motion, the resistance to P P\,P has a constant magnitude of 2 N and the resistance to Q Q\,Q has a constant magnitude of 4 N.

Find the acceleration of the particles as the system moves under the action of the 30 N force.
Find the speed of the particles after 5 seconds.
Find the tension in the rod as the system moves under the action of the 30 N force.
After 5 seconds the force is removed and the system decelerates to rest. The resistances to motion are unchanged. Find the distance moved by P P\,P as the system decelerates.
Find the thrust in the rod as the system decelerates.
30 exam-style questions on Edexcel AS Level Maths Forces and Motion, covering 10.1 Force Diagrams, 10.2 Forces as Vectors, 10.3 Forces and Acceleration, 10.4 Motion in 2 Dimensions, 10.5 Connected Particles, and 10.6 Pulleys. Each one has a worked solution and a mark scheme showing where the marks go.