A body of mass 100g moving with a velocity if 10ms−¹ collides with a wall. If after collision; it moves with a velocity of 2.0ms−¹ in the opposite direction. Calculate the change in momentum.

A. 0.8Ns
B. 1.2Ns
C. 12.0Ns
D. 80.0Ns

Correct Answer:

Option A = 0.8Ns

Explanation

Momentum = Mass x Velocity
Change in Momentum = Mass x (change in velocity)

Change in Momentum = Mass x (v – u)
Mass = 100g = 0.1kg
U = 2ms−¹
V = 10ms−¹

Change in momentum = m (v − u)
= 0.1 (10 − 2)
= 0.1 (8)
= 0.8Ns