Question

A 7kg bowling ball rolls down the lane with a velocity of 5 m/s and hits a pin, transferring half of its kinetic energy to the pin. What is the mass of the pin if energy is conserved and the pin travels at 7.5 m/s after being hit?

Answer 1

2.33 kg

Step-by-step explanation:

Momentum = p = mv

p-bowling ball before it hits the pin = (7 kg)(5 m/s) = 35 kg·m/s

Half of this p transfers to the pin after the hit: 35 kg·m/s / 2 = 17.5 kg·m/s

p-pin = 17.5 kg·m/s = m(7.5 m/s)

m-pin = (17.5 kg·m/s) / (7.5 m/s) = 2.33 kg