A cannonball with a mass of 1.0 kilogram is fired horizontally from a 500.-kilogram cannon, initially at rest, on a horizontal,
frictionless surface. The cannonball is acted on by an average force of 8.0 × 10 3 newtons for 1.0 × 10 −1 second. What is the magnitude of the change in momentum of the cannonball during firing?
The impulse J is equal to the magnitude of the force applied to the cannonball times the time it is applied: But the impulse is also equal to the change in momentum of the cannonball: If we put the two equations together, we find And since we know the magnitude of the average force and the time, we can calculate the change in momentum: