Question

calculate the change of momemtum of a body weightning 5 kg when its velocity dcreases from 20m/s to 0.20m/s'

Answer 1

Momentum is defined as mass times velocity and its a vector with same direction as veloctity.
We assume the direction of velocity remained the same and only magnitude changed here.

Initial momentum  =  P1 = m u = 5 kg * 20 m/s = 100 kg m/s
Final momentum  = P2  = m v  =  5kg * 0.2 m/s  =  1 kg m/s
Chagne in momentum  = P2 - P1 =  1- 100 = - 99  kg m/s

Answer 2

Answer:

Explanation:

Given :-

Mass of the body, m = 5 kg

Initial velocity of the body = 20 m/s

Final velocity of the body = 0.2 m/s

To Find :-

Change in momentum

Formula to be used :-

Change in Momentum = mv - mu

Solution :-

Putting all the values, we get

Change in Momentum = mv - mu

Change in Momentum = m (v - u)

Change in Momentum = 5 (0.2 - 20)

Change in Momentum = 5 × (-19.8)

Change in Momentum = - 99 kg m/s

Hence, The Change in Momentum is - 99 kg m/s.