Question

A 100 g ball moving with a velocity of 20 m/s returns in opposite direction with a velocity of 30 m/s after striking a bat. Find the impulse.

Answer 1

Let the final direction of velocity be positive.

Mass of the ball, m = 100 g = 0.1 kg
Initial velocity of the ball, u = -20 m/s
Final velocity of the ball, v = 30 m/s

Impulse experienced by the ball is equal to its change in momentum.

Impulse$=\Delta P=m(v-u)=0.1[30-(-20\left)\right]=5kgm/s$