Understanding the Concepts

* Momentum: Momentum is a measure of an object's mass in motion. It's calculated as: *momentum = mass * velocity*

* Impulse: Impulse is the change in momentum of an object. It's calculated as: *impulse = force * time*

Applying the Concepts

1. Impulse: We know the force (20 N) and the time (4 s). We can calculate the impulse:

* Impulse = 20 N * 4 s = 80 Ns

2. Change in Momentum: Since impulse is equal to the change in momentum, the change in momentum is 80 Ns.

Important Note: This calculation assumes the force acts in a single direction. If the force is applied at an angle, you'd need to consider the vector components of the force and momentum.