GCSE Combined Science Work, energy and momentum questions by topic

This question is about work done.

1. (a)State the unit of work done.[1]
2. (b)A stalled car is pushed 15 m with a steady force of 480 N. Calculate the work done.[2]
3. (c)State where the energy goes if the car is pushed along a rough surface.[1]

This question is about power doing work.

1. (a)Write the equation linking power, energy transferred and time.[1]
2. (b)A motor transfers 900 J in 5.0 s. Calculate its power.[2]
3. (c)Name the unit of power.[1]

An archer draws a bow and releases the arrow.

1. (a)Name the store filled while the bow is drawn.[1]
2. (b)Name the store the arrow's energy is in as it leaves the bow.[1]
3. (c)An 18 kg box is lifted 1.5 m (g = 10 N/kg). Calculate the work done against gravity.[2]

This question is about momentum.

1. (a)Write the equation linking momentum, mass and velocity.[1]
2. (b)Calculate the momentum of a 0.045 kg golf ball moving at 40 m/s.[2]
3. (c)State whether momentum is a scalar or a vector.[1]

A warehouse worker pushes a crate with a steady horizontal force of 340 N through 6.0 m.

1. (a)Calculate the work done by the worker.[2]
2. (b)Explain what happens to this energy if the floor is rough.[2]
3. (c)Complete the statement: work done is the energy ______ by a force.[1]

A 55 kg climber ascends a wall, gaining 6.0 m of height in 30 s. Take g = 10 N/kg.

1. (a)State what is meant by power.[1]
2. (b)Calculate the useful work done against gravity.[2]
3. (c)Calculate the climber's useful power.[2]

Two ice skaters (55 kg and 45 kg) stand facing each other and push apart. The 55 kg skater moves off at 0.90 m/s.

1. (a)State the total momentum of the pair before the push.[1]
2. (b)Calculate the momentum of the 55 kg skater after the push.[1]
3. (c)Calculate the velocity of the 45 kg skater.[2]
4. (d)Name the law used in your calculation.[1]

This question is about car safety features.

1. (a)Explain how a crumple zone reduces the force on passengers, using F t = Δ(m v).[2]
2. (b)Explain how an air bag protects the driver's head.[2]
3. (c)Name one other feature that works the same way.[1]

A 3.0 kg cannon fires a 0.012 kg ball forwards at 250 m/s.

1. (a)Calculate the momentum of the ball.[2]
2. (b)Calculate the cannon's recoil speed.[2]
3. (c)Explain why the direction of each momentum matters.[1]

A 1 200 kg car travelling at 15 m/s is brought to rest in a crash.

1. (a)Calculate the car's momentum before the crash.[2]
2. (b)The seat belt and air bag stop the driver over 2.0 s. Calculate the average force on the driver (mass 75 kg) travelling at 15 m/s.[2]
3. (c)Without the belt, the same driver would stop against the wheel in 0.050 s. Calculate that force.[2]

A 3.0 kg trolley at 4.0 m/s collides with a stationary 1.0 kg trolley and they couple together.

1. (a)Calculate their common speed after the collision.[2]
2. (b)Calculate the total kinetic energy before and after the collision.[2]
3. (c)Explain the difference between your two kinetic energy answers.[1]

A pump raises 120 kg of water through a height of 8.0 m in 40 s. Take g = 10 N/kg.

1. (a)Calculate the weight of the water.[1]
2. (b)Calculate the useful work done by the pump.[2]
3. (c)Calculate the useful power of the pump.[2]
4. (d)State one reason why the electrical power drawn from the mains exceeds your answer.[1]