Physics 9702 · AS & A Level · Turning effects of forces
Turning effects of forces — practice question
As shown in Fig. 3.1, a rod $PQ$ is fastened at $P$ to a vertical wall. The rod has a length of $1.60\,\text{m}$. Its weight $W$ acts $0.64\,\text{m}$ from $P$. A wire attached to $Q$ and to the wall at $R$ keeps the rod horizontal and in equilibrium. The wire exerts a force $F$ on the rod of $44\,\text{N}$ at $30^\circ$ to the horizontal.
(a(i))[1]
Find the vertical component of $F$.
(a(ii))[1]
Find the horizontal component of $F$.
(b)[2]
Using moments about $P$, determine the weight $W$ of the rod.
(c)[1]
Explain why the wall must exert a force on the rod at $P$.
(d)[1]
On Fig. 3.1, draw an arrow to show the force acting on the rod at $P$. Label the arrow $S$.
Worked solution & mark scheme
This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “vertical component is $44\sin30^\circ=22\,\text{N}$” …