OCR GCSE Physics B (21st Century) Paper 1 November 2021 question paper

Nina is a mountain climber.

Calculate the increase in her stored gravitational energy when she climbs a mountain which has a vertical height of 750 m.

Her mass is 70 kg.

Gravitational field strength = 10 N / kg.

Use the equation: gravitational potential energy = mass × gravitational field strength × height

What is the useful energy store in Nina’s muscles before she climbs the mountain?

Tick (✓) one box.

Nina returns to her starting point at the bottom of the mountain and stops.

Which two energy stores have increased when Nina reaches the bottom of the mountain and stops?

Tick (✓) two boxes.

Jane investigates a small electrical heater in an electrical circuit.

The resistance of the heater when it is first switched on is 1.4 .

The current in the heater is 9.0 A.

Calculate the potential difference across the heater.

Use the equation: potential difference = current × resistance

Jane adjusts the potential difference across the heater to 12 V.

The current in the heater is now 8.6 A.

Calculate the electrical power of the heater.

Use the equation: power = potential difference × current

The temperature of the heater increases.

Predict what happens to the resistance of the heater.

Beth and Kareem make waves on a rope.

Kareem Beth

Beth’s description of the wave is incorrect.

State the correct amplitude and wavelength.

The amplitude is........ cm.

The wavelength is........ m.

Kareem describes the waves another way.

Describe how the waves on the rope are an example of transverse waves.

How are sound waves in air different to the waves on the rope?

Jamal sees a ‘salt lamp’ in a shop, as shown in the diagram.

The salt lamp contains a white light bulb covered with blocks of salt.

Which two statements about visible light waves are correct?

Tick (✓) two boxes.

When the lamp is switched on, visible light passes through the salt as it leaves the lamp. The salt lamp appears yellow.

Complete the sentence to explain why the salt lamp appears yellow.

The salt lamp appears yellow because the salt........ yellow light

and........ all the other colours of white light.

Jamal sees this claim on the packaging for the salt lamp.

Describe the peer review process.

Jack has a wax candle.

The density of the wax in the candle is 0.9 g / cm³. (a)

The total volume of wax in the candle is 11 cm³.

Calculate the mass of wax in the candle.

Jack lights the candle.

After a few minutes, Jack notices that some of the wax is still solid, and some of it has melted. Approximately 0.6 g of wax has melted.

Calculate the thermal energy needed to melt 0.6 g of wax.

Specific latent heat of melting of wax = 210 000 J / kg

Use the equation: energy to cause a change of state = mass × specific latent heat

Jack blows out the candle.

The liquid wax turns back into a solid.

Describe what happens to the particles in the wax as it changes from a liquid into a solid.

Eve does an experiment to investigate the relationship between pressure and volume of a gas.

She uses a syringe containing air. She compresses the air by placing some books on top of the

The mass of one book is 0.85 kg.

Calculate the weight of this book.

Use the equation: weight = mass × gravitational field strength

Gravitational field strength = 10 N / kg.

The total weight of the books on top of the syringe is 24 N. The surface area of the syringe in contact with the books is 0.0028 m².

Calculate the pressure on the air in the syringe due to the weight of the books.

Use the equation: pressure = force normal to a surface ÷ area of that surface

Give your answer to 2 significant figures.

Eve observes that as the pressure increases, the volume of the air in the syringe decreases.

Explain this observation using ideas about particles.

Eve talks about the experiment.

How could Eve keep the temperature of the air in the syringe constant?

Tick (✓) one box.

Kai is a builder. He uses a conveyor system to lift bricks up to the roof of a house, as shown in the diagram.

The conveyor system is powered by an electric motor, which is connected to a petrol generator.

The petrol used by the generator is a store of chemical energy.

Describe two changes in stored energy as the bricks are lifted to the roof of the house.

Calculate the work done by the electric motor to lift a brick with a weight of 35 N to the roof.

Use the equation: work done = force × distance

Give the correct unit for your answer.

Kai considers using a conveyor system with a higher power rating.

Explain what is meant by the power of the conveyor system.

Suggest how a higher power conveyor system could help Kai lift bricks up to the roof of a house.

Sarah investigates the effect of frictional forces on a sliding object. She uses a block of wood which is on a table, as shown in Fig. 8.1.

She pushes the block with her hand to start it moving. She then releases it and waits for it to come to rest.

Block Table

Fig. 8.1

One of the forces acting on the block is friction. This friction force acts to the left, as shown in Fig. 8.1.

Describe one other force acting on the block after Sarah has released it.

Why does the block slow down when it is released?

To measure the speed of the block, Sarah uses a light gate, as shown in Fig. 8.2.

Block Light gate Timer Table

The light gate measures the time that the block takes to pass through it. In one test, the block takes 0.60 seconds to pass through the light gate.

The length of the block is 15 cm.

Calculate the average speed of the block as it passes through the light gate.

Use the equation: average speed = distance ÷ time

Average speed =........ m / s

Sarah wants to do an experiment to investigate how the initial speed of the block affects the distance the block travels before stopping.

Suggest how Sarah could do this experiment.

The UK government plans to build more nuclear power stations in the future.

Why is nuclear fuel a non-renewable energy source?

Nuclear power stations use uranium as a fuel. Energy is released from the uranium nuclei by nuclear fission.

Describe the process of nuclear fission.

A typical nuclear power station has a useful power output of 1600 MW.

The total power input is 4000 MW.

Calculate the efficiency of a typical nuclear power station.

Give your answer as a percentage.

The chart shows typical thinking distances and braking distances for a car in normal driving conditions.

Estimate the total stopping distance of a car travelling at a speed of 45 mph, using the chart.

Total stopping distance = thinking distance + braking distance

Some residential areas are reducing their speed limits from 30 mph to 20 mph.

Explain why reducing the speed limit improves road safety.

Use data from the chart in your answer.

Ben looks at the chart.

Discuss Ben’s statement.

Use data from the chart in your answer.

Speed is a factor which affects the total stopping distance of a car in an emergency.

State one other factor, and explain why it affects the total stopping distance.

Factor........

Explanation........

Some types of nut are slightly radioactive. They emit alpha radiation.

Amaya uses a radiation detector to measure the radiation given out by some nuts.

Li comments that there is a problem with Amaya’s experiment.

Suggest how to solve this problem.

Explain how Amaya could find out if the radiation that she detects is alpha radiation.

Amaya’s teacher says that there is an electric current flowing between the nuts and the radiation detector.

Explain why Amaya’s teacher is correct.

Suggest why people still eat nuts, even though they know that some types are slightly radioactive.

Sundip wants to measure Alex’s reaction time.

Their teacher gives them a 30 cm ruler, and the table shown.

Explain how to use the ruler and the table to measure Alex’s reaction time.

You can draw a diagram to support your answer.

Suggest why the table does not include values below 12 cm.

Sundip wants to use the 30 cm ruler to measure the reaction times of her class.

Explain why Sundip is correct and suggest one solution to this problem.

A large percentage of electricity in the UK is generated using wind turbines and gas-fired power stations.

The graph compares the percentage of UK energy generated by wind and gas from January to March 2017.

Each plot point shows the energy generated in one day.

Percentage of UK energy generated by gas (%)

Describe and explain the relationship shown in the graph.

Mia and James discuss the data.

Give one reason why Mia is correct.

Discuss James’ comment.

An atomic clock is a very accurate way of measuring time.

Many atomic clocks use electromagnetic radiation emitted from caesium atoms.

Explain how an atom can emit electromagnetic radiation.

The frequency of electromagnetic radiation emitted from caesium atoms is 9.19 × 10⁹ Hz. (b)

Calculate the wavelength of this radiation.

Speed of light = 3.0 × 10⁸ m / s.

Satellite navigation systems rely on atomic clocks for their accuracy.

Suggest one way that society has benefited from the invention of accurate satellite navigation systems.