Fig. 2.1 displays a wooden metre ruler that is balanced and uniform. Its width measures $2.6 \times 10^{-2}\,\text{m}$, while its thickness measures $6.0 \times 10^{-3}\,\text{m}$.
(a)[1]
Define the ‘moment’ of a force using words.
(b)[1]
On Fig. 2.1, place a point labelled X to show the centre of gravity of the metre ruler. State the distance from the 0 cm end of the ruler to X.
(c(i))[3]
Show that the metre ruler has a mass of $0.081\,\text{kg}$.
(c(ii))[2]
Calculate the density of the wood used for the metre ruler.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “moment means force \times perpendicular distance from the pivot” …