Momentum - exam practice

In a test a 500 kg car travelling at 10 m s^–1 hits a wall. The front 0.30 m of the car crumples as the car is brought to rest.

What is the average force on the car during the impact?

A car of mass 580 kg collides with the rear of a stationary van of mass 1200 kg.

Following the collision, the van moves with a velocity of 6.20 m s⁻¹ and the car recoils in the opposite direction with a velocity of 1.60 m s⁻¹.

What is the initial speed of the car?

What is true for an inelastic collision between two isolated objects?

Two ball bearings X and Y are projected from horizontal ground at the same time.

X has mass 2m and is projected vertically upwards with speed u.

Y has mass m and is projected at 30° to the horizontal with speed 2u.

Air resistance is negligible.

Which statement is correct?

A body of constant mass falls freely due to gravity.

The rate of change of momentum of the body is equal to its

A ball, initially at rest, is struck by a hockey stick. It leaves the hockey stick at speed v.

Which quantity, together with the mass of the ball, can be used to determine v?

A puck of mass 0.16 kg is sliding on ice with a constant velocity of 11.0 m s⁻¹. A hockey stick exerts a force on the puck, for a short period of time, in the opposite direction to the velocity of the puck.

The momentum of the puck changes by 2.0 kg m s⁻¹.

Ignore friction.

What is the speed of the puck when it leaves the hockey stick?

A javelin thrower exerts a force of 100 N on a javelin for a time of 0.30 s.

The javelin has a mass of 0.80 kg.

What is the rate of change of the momentum of the javelin?

A trolley of mass 1.0 kg is moving on a horizontal surface at a constant velocity of 2.0 m s⁻¹. A force of 3.0 N is applied to the trolley in the opposite direction to its motion for a time of 1.5 s and then the force is removed.

What is the magnitude of the final momentum of the trolley?