An object gains kinetic energy as its velocity increases from 2.0 m/s to 10 m/s. Using the impulse-momentum theorem, FΔt = Δp, the impulse provided was 850 Ns. A gas molecule maintains its kinetic energy and reverses its momentum direction when elastically colliding with a container wall. Impulse is measured in newton seconds (Ns) as it equals the change in an object's momentum.