 # Q: Match the following:If net force on a rigid body is zero then,A. Linear velocity of COM                                                                                             1. Is ZeroB. Angular Velocity of the rigid body                                                                              2. Is ConstantC. Angular momentum about an axis passing through the COM                                       3. May be varyingD. Angular momentum about an axis not passing through the COM                                  4. Can’t be said(Please explain the various possible cases.)

12 years ago

A: the acceleration of COM = net force/mass. therefore linear velocity of centre of mass is constant

B:consider, for example, a couple(a pair of anti-parallel forces equal in manitude,and symmetric about the COM) acting on the rigid body. the torque is nonzero, therefore, answer- may be varying

C:Same as above

D: modify case B by moving the couple parallel to itself such that it is symmetric about this new axis. it is then obvious that angular velocity about this axis may be varying