Understanding the Concepts

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

* Momentum (p) = mass (m) * velocity (v)

* Rate of Change of Momentum: This is the same as impulse, which is the change in momentum over a period of time. It's calculated as:

* Impulse (Δp) = Force (F) * Time (Δt)

Solving the Problem

1. Calculate the impulse:

* Impulse (Δp) = 4 N * 2 s = 8 Ns

2. Rate of change of momentum: Since impulse is the change in momentum, the rate of change of momentum is simply the impulse itself:

* Rate of change of momentum = 8 Ns

Answer: The rate of change of momentum (or impulse) is 8 Ns.