A piece of putty moving with 1 unit of momentum strikes and sticks to a heavy bowling ball initially at rest. After the putty sticks to the ball, both move with a combined momentum of

A girl pushes a cart to the left with a 100-N force. At the same time a boy pushes it to the right with a 50-N force. The net force exerted on the cart is

A stone is thrown horizontally from the top of a cliff. One second after leaving your hand it drops a vertical distance of

A 30-kg girl on friction-free roller blades pushes away a 25-kg boy also on roller blades at 1 m/s. The girl’s speed is

A stone is thrown vertically upward. At the top of its vertical path the force acting on it is

If there were no gravity, a ball thrown upward at an angle would follow a straight-line path. Due to gravity, however, at the end of 1 s it is

A push on a 1-kg brick accelerates the brick. Neglecting friction, to equally accelerate a 10-kg brick requires the force to be

With no air resistance, a projectile fired at 50° has the same range as if it were fired at

If a weighted air-filled balloon sinks in deep water, it will

An open freight car rolls friction-free along a horizontal track in vertically pouring rain. As water accumulates in the car, its speed