Question

a football of mass 150 grams moving with a velocity of 20 ms is struck by a player such that it shoots back along the same path with a velocity of 15ms. calculate the change in momentum produced

Answer 1

Mass of football = 150g = 0.15kg

Initial velocity, u = 20 m/s

After striking, the ball moves back along the same path with velocity 15 m/s. So v = -15 m/s

Change in momentum, ∆P = |m(v-u)|

∆P = |0.15×(-15 - 20)|

∆P = |0.15×35|

∆P = 5.25 kg.m/s

Hence change in momentum is 5.25 kg.m/s

Answer 2

Heya, Here is your answer :-

u = 20m/s
v = 15m/s
m = 150 g = 0.15kg

$change \: in \: momentum \: = mv \: - \: mu$
So,
Change in Momentum = 0.15*15 - 0.15*20 = 2.25 - 3 = - 0.75 kg-m/s

So,
Change in Momentum is -0.75 kg-m/s.