Q 13.     A hockey ball of mass 200 g travelling at 10 m s-1 is struck by a hockey stick so as to return it along its original path with a velocity at 5 m s-1.  Calculate the magnitude of change of momentum occurred in the motion of the hockey ball by the force applied by the hockey stick.

Answers (1)
S Sanket Gandhi

The change in the momentum is given by :

                                          \Delta p\ =\ m\Delta v

or                                                 =\ 0.2\times (-5\ -\ 10)

or                                                 =\ -3\ Kg\ m/s

In the above equation, we have taken   v\ =\ -5\ m/s    as its direction is opposite.