A shop worker is stacking the shelves in a supermarket. 

They lift tins of soup from pallets on the ground and place them on a shelf 1.2 m off the ground. 

Each tin has a mass of 350 g.

Calculate the weight of each tin of soup.

State the equation linking work done, force, and distance moved.

Calculate the work done when a pack of 12 tins are lifted onto the shelf. 

It takes 20 s to put all 12 tins on the shelf. 

Calculate the power of the shop worker lifting the tins.

Give your answer to 2 decimal places.

A student is using resistance bands to exercise. 

The student stretches the band with spring constant 150 N m^-1.

At full extension the band stored 50 J.

Calculate the extension of the band at full extension.

Give your answer in m, to 2 decimal places.

The student stretches the band to full extension 15 times in 40 s. 

Calculate the student's power output while stretching the resistance band.

Give your answer to 2 decimal places.

A student is investigating the force needed to push a box up a ramp.

State the equation linking work done, force, and distance moved.

The student pushes the block 40 cm along the ramp.

The work required to do this is 6 J.

Calculate the force exerted on the block by the student.

The box gains 1.8 J of gravitational potential energy when it is pushed to the top of the ramp.

Calculate the mass of the box in kg.

Explain why the work done on the box is greater than the increase in GPE store of the block.

A cyclist is cycling along a horizontal road at 15 m s^-1. 

The cyclist and bicycle have a combined mass of 100 kg. 

Calculate the kinetic energy of the cyclist and bicycle. 

The cyclist applies the brakes and slows down to 6 m s^-1. 

Calculate the work done in slowing the bicycle to 6 m s^-1.

Describe the energy transfers that take place as the brakes slow the bicycle from 15 m s^-1 to 6 m s^-1.

The brakes slowed the bike from 15 m s^-1 to 6 m s^-1 over a distance of 30 m. 

Calculate the average braking force on the bike.

This question is about work done, power, and efficiency.

Which of these is not a unit for power?

A box is pushed with a force of 120 N. 

The box moves a total distance of 26 cm.

Which of the following represents the work done on the box?

A cyclist applies the brakes to slow their speed from 8 m s^-1 to rest.

The mass of the cyclist and bicycle is 89 kg. 

Which of the following represents the work done by the brakes on the bike?

An electric motor has an input of 250 W.

The efficiency of the motor is 49%. 

Calculate the useful output power of the motor.

A student is using an electric motor to lift a mass off the ground. 

The motor operates at 12 V with a current of 20 mA.

Calculate the power of the motor.

The motor is 60% efficient. 

Calculate the useful energy output per second.

Give your answer to 2 decimal places.

The mass being lifted is 200 g. 

Calculate the gravitational potential energy of the mass when it has been lifted through a distance of 80 cm.

Calculate how long it takes for the motor to lift the 200 g mass to a height of 80 cm.

Give your answer to 1 decimal place.

This question is about the forces and work done when an archer loads a bow.

State the name of the energy store that increases as the archer pulls the string of the arrow back.

When the 150 g arrow is released, it has a speed of 80 m s^-1. 

Calculate the kinetic energy of the arrow.

The elastic potential energy stored in the bow before the archer released was 560 J. 

Calculate the efficiency of conversion from elastic potential energy to kinetic energy.

Give your answer to 2 significant figures.

The arrow is brought to rest when it hits the target. 

State the work done on the arrow when it hits the target. 

Sarah rides an electric scooter to work. 

The scooter has a mass of 48 kg. The maximum distance the scooter can travel on level ground is 10 km when carrying a rider of mass 63 kg and travelling at its maximum speed of 2.5 ms^-1.

The scooter battery has an emf of 12 V and can deliver 3.17 x 10⁴ C in one full charge.

Calculate the average power of the scooter.

During the journey to work, Sarah travels along a long road which has an incline of 5° to the horizontal. 

Calculate the force that gravity exerts on the scooter and Sarah parallel to the slope. 

Calculate the maximum speed the Sarah can ride the scooter up the inclined road. 

The resistive forces due to air resistance and friction are 38 N.

Explain how and why the maximum range of the scooter on level ground is affected by

• the mass of the user
• the speed at which the scooter travels

A solar powered drone, equipped with a battery, allows photographers to capture aerial shots during long flights. 

The drone has a mass of 2 kg. On a sunny day, it can fly continuously for 4 hours at a maximum speed of 10 ms^-1 before the battery is depleted. The battery, when fully charged by its solar panels has an emf of 15 V and can deliver 1.44 x 10⁴ C.

Determine the average power output of the battery during the drones flight. 

Calculate the average resistive forces experienced by the drone.

The drone flies upwards at its maximum speed. 

Calculate the lift force that the drones rotors must provide.

An electric motor is used to pull a heavy crate containing building supplies up a ramp.

The building supplies and trolley are pulled up the ramp by an electric motor which is connected to a 24 V battery of negligible internal resistance.

The graph below shows how the current in the motor varies with time.

Calculate the total energy input to the motor during the first 250 ms.

During the first 250 ms the motor pulls the building supplies and trolley through a vertical distance of 8 cm at a speed of 0.65 ms^-1. 

The average efficiency of the motor during the first 250 ms is 25.15%.

Calculate the combined mass of the trolley and building supplies.

The trolley is travelling up the slope at 0.65 ms^-1 when the rope snaps. 

Calculate the speed of the trolley and building supplies when they reach the bottom of the slope.

You may assume air resistance and friction are negligible.

The rope used to pull the trolley and building supplies up the ramp had a diameter of 16 mm. 

Calculate the stress in the rope just before it snapped.