Two wooden planks, AB and BC, are set at $15^\circ$ to the horizontal. They are connected at B, as shown in Fig. 2.1. A small metal block M is released from rest at A. It moves down to B and then continues up the other plank to C. A and C are each $0.26\,\text{m}$ above B. Take frictional forces to be negligible.
(a(i))[3]
Describe and explain how the acceleration of M changes as it moves from A to B and then from B to C.
(a(ii))[3]
Calculate how long M takes to move from A to B.
(a(iii))[2]
Calculate the speed of M at B.
(b)[2]
The plank BC is changed so that it makes an angle of $30^\circ$ with the horizontal. M is released from rest at A and travels down to B. It then moves a distance along the plank from B towards C. Use the law of conservation of energy to work out this distance. Show your working.
Worked solution & mark scheme
This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Accelerations from A to B and B to C have same magnitude” …