Assume the bike has a mass of 20 kg and is moving down at - 9 m/s when it is thrown off the balcony. When the bike hits the ground it still has a mass of 20 kg but the bike is not longer moving. What is the change in momentum of the bike?

180 kgm/s

Explanation:

From Newton's second law of motion,

ΔM = m (v-u) ... Equation 1

Where ΔM = change in momentum of the bike, m = mass of the bike, v = final velocity of the bike, u = initial velocity of the bike.

Given: m = 20 kg, u = - 9 m/s, v = 0 m/s (the bike is no longer moving)

Substitute into equation 1

ΔM = 20[0 - (-9) ]

ΔM = 20 (9)

ΔM = 180 kgm/s.

Hence the change in momentum of the bike = 180 kgm/s