(a)[4]
Find the greatest value of $T$ for which the ring remains at rest.
(b)[3]
Find the ring's acceleration when $T = 3$.
Mathematics 9709 · AS & A Level · Forces and equilibrium
Forces and equilibrium — practice question
The diagram depicts a ring of mass $0.1\,\text{kg}$ passed onto a fixed horizontal rod. The rod is rough, with coefficient of friction between the ring and the rod equal to $0.8$. A force of magnitude $T\,\text{N}$ acts on the ring at an angle of $30^\circ$ to the rod, directed downwards in the vertical plane that contains the rod. At the start, the ring is at rest.