Question

A 3kg crab was moving at 1 m/s on the shore before the tide pushed him for 5 seconds. If his final speed was 3 m/s, what force did the tide push him with?

Answer 1

Answer:

1.2 N

Explanation:

Impulse = change in momentum

J = Δp

FΔt = mΔv

F (5 s) = (3 kg) (3 m/s − 1 m/s)

F = 1.2 N

Alternatively, force = mass × acceleration

F = ma

F = m Δv / Δt

F = (3 kg) (3 m/s − 1 m/s) / (5 s)

F = 1.2 N