The force applied over a period of time that is required to give a stationary object momentum is called impulse.

Here's why:

* Momentum: Momentum is the mass of an object multiplied by its velocity (p = mv). A stationary object has zero momentum.

* Impulse: Impulse is the change in momentum of an object. It is calculated as the force applied multiplied by the time over which the force acts (Impulse = FΔt).

Therefore, to give a stationary object momentum, you need to apply a force for a certain amount of time, which is the impulse.