An air bag applies a force of 6100 n to bring about a change in momentum of 3540 kg m/s. how much time did it act over a. 0.26 s b. 6.1 s c. 0.58 s d. 35 s e. 1.7 s

The correct answer is C) 0.58 s.

In fact, Newton's second law says that the force applied to an object is the product between the mass and the acceleration of the object:

but the acceleration is the change of velocity in a time :

So F becomes

Remembering that the momentum is the product between mass and velocity:

The numerator in the formula of F is the change in momentum:

So we can find the interval of time the force acts: