Question

A golden retriever is sitting in a park when it sees a squirrel. The dog starts running, exerting a constant horizontal force of 89 N against the ground for 3.2 seconds. What is the magnitude of the dog's change in momentum?

Answer 1

Answer:

284.8 kgm/s

Explanation:

Impulse: This can be defined as the product of force and time of a body. The S.I unit of impulse is N.s mathematically.

Impulse = Force × time

Change in momentum: This is the product of the mass of a body and its change in velocity. The unit of change in momentum is kgm/s.

Mathematically,

momentum = mass×change in velocity

Deduction from newton's second law of motion,

Impulse = change in momentum

Therefore,

Change in Momentum = Force×time

ΔM = F×t................. Equation 1

Where F = force = 89 N, t =time =  3.2 s.

Substitute into equation 1

ΔM = 89×3.2

ΔM = 284.8 kgm/s

Thus the change in momentum = 284.8 kgm/s