Physics

Figure 4 shows a person sliding down a zip wire.

Describe how the vertical height of the tower could be measured accurately.

When using the zip wire, the person moved through a vertical height of 2.0 m.
The person has a mass of 45 kg.
gravitational field strength = 9.8 N/kg.
Calculate the change in gravitational potential energy of the person.
Use the equation:
gravitational potential energy = mass × gravitational field strength × height

Give three factors that affected the kinetic energy of the person as she reached the bottom of the zip wire.

Figure 6 shows how different energy resources were used in the United Kingdom (UK) to generate electricity on one day in June 2018. The UK government plans to stop using coal-fired power stations by 2025.

Explain one environmental problem caused when electricity is generated by burning coal.

Give two renewable energy resources that could make up the ‘Other’ energy resources in Figure 6.

Determine the percentage of electricity generated in nuclear power stations that day.
Use data from Figure 6.

Figure 7 shows how the demand for electricity varied with the time of day.

What was the difference between the maximum demand and minimum demand for electricity during this day?

Figure 7 shows that the demand for electricity increased between 06:00 and 09:00.
Solar power could have met the demand if there were enough solar panels installed in the UK.
Explain why.

An electric car has a motor that is powered by a battery. A diesel car has an engine that is powered by diesel fuel. Table 2 compares an electric car and a diesel car.

Give two advantages of the diesel car compared with the electric car in Table 2.

The mass of the battery in the electric car is 420 kg.
The total mass of the electric car is 1610 kg.
Calculate the mass of the battery as a percentage of the total mass of the electric car.

Designers of electric car batteries want to increase the amount of energy that can be stored in a battery.
Suggest two reasons why.

Write down the equation which links energy transferred, power and time.

The charger has a power output of 7000 W.
Calculate the time taken to transfer 420 000 J of energy to the car battery.

Figure 9 shows a circuit diagram.

In which position could a switch be placed so that both lamps can be switched on or off at the same time?

Draw the circuit symbol for a switch in the box below.

In 30 seconds, 24 coulombs of charge flow through the battery.
Calculate the current in the battery.
Use the equation:
current = charge flow / time

There is a potential difference of 3.6 V across the battery.
Calculate the energy transferred by the battery when 60 coulombs of charge flows through the battery.
Use the equation:
energy transferred = charge flow × potential difference

A student built Circuit X and Circuit Y shown in Figure 10. The components used in each circuit were identical.

How would the reading on the ammeter in Circuit Y compare to the reading on the ammeter in Circuit X?

How does the total resistance of Circuit Y compare with the total resistance of Circuit X?

The student built another circuit which is shown in Figure 11.

Write down the equation which links current, potential difference and resistance.

There is a potential difference of 3.6 V across the lamp in Figure 11.
The current through the lamp is 0.80 A.
Calculate the resistance of the lamp.

A student carried out an experiment to determine the specific heat capacity of water. Figure 12 shows the equipment the student used to heat the water.

Why did the student insulate the beaker of water?

One hazard in this experiment is the hot water.
Give one risk to the student caused by this hazard.

This question is about temperature changes. A student investigated the change in temperature of a solution when different masses of ammonium nitrate were dissolved in water.
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This is the method used.
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1. Measure 200 cm3 of water into a polystyrene cup.
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2. Measure the temperature of the water.
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3. Add 4.0 g of ammonium nitrate to the water.
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4. Stir the solution until all the ammonium nitrate has dissolved.
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5. Measure the lowest temperature reached by the solution.
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6. Repeat steps 1 to 5 with different masses of ammonium nitrate.
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Give the independent variable and the dependent variable in the investigation.
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Independent variable: ____________
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Dependent variable: ______________

Plot the data from Table 6 on the graph paper. Draw a line of best fit.<br/><br/>Table 6<br/><br/>| Mass of ammonium nitrate (g) | Lowest temperature (°C)
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Determine the initial temperature of the water. You should extend your line of best fit on the graph.

How do the results show that dissolving ammonium nitrate in water is endothermic?

The student repeated the experiment for 8.0 g of ammonium nitrate three more times. The student recorded the mean lowest temperature as 16.5 ± 0.3 °C. Explain why the student included ± 0.3 °C after the mean lowest temperature.

What type of error is shown by the results in Table 7?

Wind turbines may generate electricity when the electricity is not needed. Two methods that can be used to store the energy from the turbine are:
Method A: Heating water to a high temperature.
Method B: Pumping water uphill into a reservoir.

Which energy store increases when water is heated?