CAIE M2 2005 November — Question 6

Exam BoardCAIE
ModuleM2 (Mechanics 2)
Year2005
SessionNovember
TopicCircular Motion 2

6
\includegraphics[max width=\textwidth, alt={}, center]{a20a6641-d771-4c89-b40f-168a0c61f99d-4_673_773_269_685} A horizontal circular disc of radius 4 m is free to rotate about a vertical axis through its centre \(O\). One end of a light inextensible rope of length 5 m is attached to a point \(A\) of the circumference of the disc, and an object \(P\) of mass 24 kg is attached to the other end of the rope. When the disc rotates with constant angular speed \(\omega\) rad s \(^ { - 1 }\), the rope makes an angle of \(\theta\) radians with the vertical and the tension in the rope is \(T \mathrm {~N}\) (see diagram). You may assume that the rope is always in the same vertical plane as the radius \(O A\) of the disc.
  1. Given that \(\cos \theta = \frac { 24 } { 25 }\), find the value of \(\omega\).
  2. Given instead that the speed of \(P\) is twice the speed of the point \(A\), find
    (a) the value of \(T\),
    (b) the speed of \(P\).