question_answer 30)

A motorcar of mass 1200 kg is moving along a straight line with a uniform velocity of 90 km/h. Its velocity is slowed down to 18 km/h in 4 s by an unbalanced external force. Calculate the acceleration and change in momentum. Also calculate the magnitude of the force require.  

Answer:

Here, mass, m = 1200 kg Initial velocity, Final velocity, Time, Acceleration, (ii) Change in momentum Magnitude of change in momentum = 24000 kg (iii) Force, F = ma = 1200(-5) = - 6000 N  Magnitude of force = 6000 N.