IGCSE Physics Momentum topical questions

State the missing quantity or unit.

1. (a)Name the equation linking momentum, mass and velocity.[1]
2. (b)State the unit of momentum.[1]
3. (c)State whether momentum is a scalar or a vector.[1]

A van of mass 2000 kg travels at 12 m/s along a straight road.

1. (a)Calculate the momentum of the van.[2]
2. (b)The van slows to 6.0 m/s. Calculate its new momentum.[1]

A hockey stick exerts an average force of 180 N on a puck for 0.020 s.

1. (a)Write the equation linking impulse, force and time.[1]
2. (b)Calculate the impulse given to the puck.[2]
3. (c)State the puck’s change of momentum.[1]

A 50 kg girl runs north at 4.0 m/s. Her 20 kg younger brother cycles north at 5.0 m/s.

1. (a)Calculate the girl’s momentum.[2]
2. (b)Calculate the brother’s momentum.[1]
3. (c)Calculate the total momentum of the pair.[1]

A railway wagon of mass 8000 kg rolling at 2.0 m/s couples with a stationary wagon of mass 4000 kg.

1. (a)Calculate the total momentum before the coupling.[1]
2. (b)Calculate the common velocity of the coupled wagons.[3]

A 0.020 kg pellet is fired horizontally at 150 m/s and embeds itself in a 0.48 kg wooden block hanging at rest on long strings.

1. (a)Calculate the momentum of the pellet just before impact.[2]
2. (b)Calculate the velocity of the block and pellet immediately after impact.[3]

A 70 kg runner moving right at 8.0 m/s is tackled by a 90 kg defender moving left at 6.0 m/s. They lock together.

1. (a)Taking right as positive, calculate the total momentum before the tackle.[2]
2. (b)Calculate the velocity of the pair after the tackle.[3]

A cannon of mass 600 kg, initially at rest on level ground, fires a 5.0 kg cannonball horizontally at 240 m/s.

1. (a)Calculate the momentum of the cannonball as it leaves the barrel.[1]
2. (b)Calculate the recoil velocity of the cannon.[3]
3. (c)Explain why the cannon’s recoil speed is so much smaller than the ball’s speed.[1]

A fielder catches a 0.17 kg cricket ball moving horizontally at 30 m/s and brings it to rest in 0.10 s.

1. (a)Calculate the momentum of the ball before the catch.[2]
2. (b)Calculate the average force the hands exert on the ball.[2]
3. (c)Fielders often draw their hands backwards while catching. Explain why this hurts less.[1]

A car of mass 900 kg travelling at 15 m/s crashes into a rigid wall and stops in 0.12 s.

1. (a)Calculate the change of momentum of the car.[2]
2. (b)Calculate the average force exerted on the car by the wall.[2]
3. (c)The car is rebuilt with a crumple zone so the same crash takes 0.40 s. Calculate the new average force and explain the effect of the change.[2]

Two frictionless trolleys collide head-on on a level track and rebound separately. Trolley P (mass 2.0 kg) moves right at 5.0 m/s before the collision and left at 1.0 m/s after. Trolley Q (mass 3.0 kg) moves left before the collision and right at 2.0 m/s after.

1. (a)Taking right as positive, write the conservation-of-momentum equation for the collision.[2]
2. (b)Calculate the velocity of Q before the collision.[3]
3. (c)State how the total kinetic energy before the collision compares with the total afterwards, and justify your answer with one calculation.[1]

A 0.60 kg ball strikes a wall perpendicularly at 15 m/s and rebounds along its original path at 9.0 m/s. The ball is in contact with the wall for 0.050 s.

1. (a)Taking the initial direction as positive, calculate the change of momentum of the ball.[2]
2. (b)Calculate the size of the average force the wall exerts on the ball. Give your answer to 2 significant figures.[2]
3. (c)State the size and direction of the average force the ball exerts on the wall.[1]