An irregular lamina lying in a plane has a mass of $50\,\text{g}$. It is suspended from a nail passing through a small hole H close to the edge of the lamina.
The nail serves as a pivot and the lamina is able to swing around it. The lamina is kept in the position shown in Fig. 3.1, a short distance above a horizontal bench.
The centre of gravity of the lamina is at G.
(a(i))[1]
Explain why the lamina experiences this downward force.
(a(ii))[2]
Calculate the weight of the lamina on Earth.
(b(i))[2]
Using Fig. 3.1, calculate the moment of the weight about the pivot.
(b(ii))[3]
The lamina is released from the position shown in Fig. 3.1.
Describe what happens to the lamina from the moment it is released until it stops moving.
Worked solution & mark scheme
This 8-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Earth’s gravitational field acts on it” …