Question

An object of mass 20 kg is accelerated uniformly from a velocity of 36 km/h to 54 km/h in 25 seconds. calculate the initial and final momentum of the object. also find the magnitude of the force exerted on the object.

Answer 1

Initial momentum = 20 kg x 36 km/h x (1000/3600) m/s = 200 kg m/s

Final momentum = 20 kg x 54 km/h x (1000/3600) m/s = 300 kg m/s

Change in momentum = 300 - 200 = 100 kg m/s

Force exerted = change in momentum/time

Force = 100 kg m/s / 25 s

Force = 4 kg m/s^2

Force = 4 N