Question

An object of mass 50 kg is accelerated uniformly from a velocity of 36 kmh–1

to 72 kmh–1

in 5 s.

Calculate the initial and final momentum of the object. Also, find the magnitude of the force exerted on

the object.​

Answer 1

Answer:

Given,

Mass=50 kg

Initial velocity=36 km/h=10 m/s

Therefore, initial momentum=(50*10) kg m/s=500 kg m/s

Final velocity=72 km/h=20 m/s

Therefore, final momentum=(50*20) kg m/s=1000 kg m/s

You can calculate the force in two ways

1. Change in momentum=(1000-500) kg m/s=500 kg m/s

Therefore, force acting on the body=(500/5) N=100 N

2. Acceleration of the body=(20-10)/5 m/s²=2 m/s²

Applying the formula, F=ma

Force=(50*2) N=100 N