CAIE M2 2009 November — Question 5

Exam BoardCAIE
ModuleM2 (Mechanics 2)
Year2009
SessionNovember
TopicCircular Motion 2

5
\includegraphics[max width=\textwidth, alt={}, center]{fe5c198d-5d05-4241-98f5-894ba92f7afe-3_593_828_1530_660} A horizontal disc of radius 0.5 m is rotating with constant angular speed \(\omega \mathrm { rad } \mathrm { s } ^ { - 1 }\) about a fixed vertical axis through its centre \(O\). One end of a light inextensible string of length 0.8 m is attached to a point \(A\) of the circumference of the disc. A particle \(P\) of mass 0.4 kg is attached to the other end of the string. The string is taut and the system rotates so that the string is always in the same vertical plane as the radius \(O A\) of the disc. The string makes a constant angle \(\theta\) with the vertical (see diagram). The speed of \(P\) is 1.6 times the speed of \(A\).
  1. Show that \(\sin \theta = \frac { 3 } { 8 }\).
  2. Find the tension in the string.
  3. Find the value of \(\omega\).