* Inertia: Inertia is the tendency of an object to resist changes in its motion. An object at rest will stay at rest, and an object in motion will stay in motion at a constant velocity unless acted upon by an external force.

* Force: Force is a push or pull that can cause a change in an object's motion (either starting it, stopping it, or changing its direction).

* Momentum: Momentum is a measure of an object's mass in motion. It's calculated as mass (m) times velocity (v): Momentum (p) = m * v

The Answer:

If a force acts on an object at rest, the force will overcome its inertia and cause it to move. The longer the force acts, the greater the change in momentum.

Explanation:

* Force and Momentum: Force causes a change in momentum. The greater the force, the greater the change in momentum.

* Time and Momentum: The longer the force acts, the longer the object accelerates, and the greater the change in velocity. Since momentum is directly related to velocity, a longer force application leads to a greater change in momentum.

Example:

Imagine pushing a heavy box. If you push with a small force for a short time, the box might barely budge. But if you push with a larger force for a longer time, the box will gain significant momentum and start moving quickly.