The moment of inertia of a disc about an axis through its centre, perpendicular to its plane, is
         given by MR, where R is the radius and M the mass.

   (a)  Use the parallel axis theorem to obtain an expression for the moment of inertia of the disc,
         about an axis perpendicular to its plane, through its edge (at B).                                  (5)

  
(b)  A force of 30 N is applied at point A, as shown above. If the disc has a radius of 8 m,
          determine the magnitude of the torque due to this force, abut the axis through B.   (4)

        
but r and F are perpendicular in this case and r = 2R, therefore,

  
(c)  What angular acceleration does this force impart to the disc, when it rotates about the axis
          through B ? (M = 2.5 kg)                                                                                            (4)

 
(d)   The disk is rotating at 7 rev/min (about B), when a mass of 2.5 kg is placed on its rim, at C.
         What is the angular velocity (in rev/min) of the disc (and the mass), immediately after the
         mass is positioned on it ?                                                                                           (8)

          Conservation of angular momentum gives,

   (e)   What is the (linear) speed of the mass at this time ?                                               (4)