If a constant force is applied for double the amount of time, the impulse applied doubles.

Here's why:

* Impulse is the change in momentum of an object.

* Momentum is the product of mass and velocity (p = mv).

* Impulse is also equal to the force applied multiplied by the time interval over which the force acts (Impulse = FΔt).

Since force is constant, doubling the time interval (Δt) directly doubles the impulse.