A cannon is set up in the back of a truck, but aimed backwards. The truck travels forwards and the cannon is fired in the opposite direction at the same speed the truck is travelling. If the cannonball appears to fall directly to the ground to a stationary observer on the sidewalk, explain what this looks like to a person inside of the truck.

A cannon is set up in the back of a truck, but aimed backwards. The truck travels forwards and the cannon is fired in the opposite direction at the same speed the truck is travelling. If the cannonball appears to fall directly to the ground to a stationary observer on the sidewalk, explain what this looks like to a person inside of the truck.