A 1.13 kg skateboard is coasting along the pavement at a speed of 4.28 m/s when a 0.93 kg cat drops from a tree vertically downward onto the skateboard. What is the speed of the
skateboard-cat combination?

By conservation of momentum,

Pinitial = Pfinal

m1v1 + m2v2 = (m1 + m2)*vf

m1 = mass of skateboard = 1.13 kg

m2 = mass of cat = 0.93 kg

v1 = initial velocity of skateboard = 4.28 m/s

v2 = initial velocity of cat = 0 m/s

vf = final velocity of skateboard-cat combo

So plug in the values and solve for vf,

1.13(4.28) + 0.93(0) = (1.13 + 0.93)vf

vf = 2.35 m/s

unbalanced force

explanation: