9709 P42 - Jun 2012 - Q4
4085
A ring of mass 4 kg is attached to one end of a light string. The ring is threaded on a fixed horizontal rod and the string is pulled at an angle of 25° below the horizontal (see diagram). With a tension in the string of \(T\) N the ring is in equilibrium.
(i) Find, in terms of \(T\), the horizontal and vertical components of the force exerted on the ring by the rod.
The coefficient of friction between the ring and the rod is 0.4.
(ii) Given that the equilibrium is limiting, find the value of \(T\).
