5. A motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km h-1. Its velocity
is slowed down to 18 km h-7 in 4 s by an unbalanced external force. Calculate the acceleration and change in
momentum. Also calculate the magnitude of force required.
[Ans. a. - 5 m 5-2 b. - 24000 kg m si c. -6000 N]​