(a(i))[1]
Calculate the weight of this lid.
(a(ii).1)[2]
Because the lid is uniform, its centre of mass is at its centre. The lid’s weight creates a moment about the hinge. Calculate the moment about the hinge when the lid is closed.
(a(ii).2)[1]
The moment needed to open the lid is greater than the value found in (a)(ii)1. Suggest one reason for this.
(b)[1]
The lid is shut. To open the lid, a force $F$ is applied to the handle as shown in Fig. 3.1. The direction of $F$ is vertically upwards and $F$ is the smallest possible force that opens the lid. A force on the handle in any other direction must be larger than $F$ in order to open the lid. Explain why.