You're viewing free preview questions. Upgrade to access more MYP5 questions.Upgrade

Work and Energy

Work and Energy — Free MYP5 Physics Practice Questions

1QuestionConduction in Solids and Thermal ConductorsConcept Practice

2 marks~3 minCriterion D

A homeowner is choosing between two wall insulation materials: expanded polystyrene foam and standard concrete. Thermal conductivity of foam is approximately 0.04 W m⁻¹ K⁻¹; thermal conductivity of concrete is approximately 1.7 W m⁻¹ K⁻¹.

Explain how thermal conductivity determines which material is more effective at reducing heat loss through the walls of the house. [2]

Solutions

2QuestionInsulation Techniques and Practical ApplicationsConcept Practice

3 marks~5 minCriterion A

Modern buildings use cavity wall insulation, where mineral wool or rigid foam panels are fitted between the inner and outer brick layers to reduce heat loss.

Identify the primary heat transfer process that cavity wall insulation is designed to reduce, and state one property of the insulating material that makes it effective. [1]

Explain how trapped air within the insulating material reduces heat transfer through the wall. [1]

Discuss one limitation that reduces the long-term effectiveness of cavity wall insulation in a real building. [1]

Solutions

3QuestionIdentifying Input and Output Energy FormsConcept Practice

3 marks~5 minCriterion A

An electric car uses a lithium-ion battery pack and an electric motor to produce motion.

State the sequence of energy transformations that occurs from the stored energy in the battery to the movement of the car. [1]

Explain how the electric motor converts electrical energy into kinetic energy of the vehicle. [1]

Discuss one societal benefit and one societal limitation of widespread electric car adoption, referring to the energy transformations involved. [1]

Solutions

4QuestionEnergy Flow in SystemsConcept Practice

2 marks~3 minCriterion A

The Hoover Dam on the Colorado River stands 221 m above its turbine inlets. Water released from the reservoir accelerates downward through penstocks before striking the turbine blades.

Describe the primary energy transformation that occurs as the water falls from the reservoir surface to the turbine inlet. [2]

Solutions

5QuestionEnergy Transformations and Real-Life ExamplesConcept Practice

2 marks~3 minCriterion A

An incandescent lightbulb is connected to a mains power supply. The filament glows white-hot, producing visible light, while the glass bulb becomes too hot to touch.

State the main form of energy entering the lightbulb. [1]

The lightbulb is described as inefficient. Identify the two main forms of energy that exit the lightbulb and explain why their relative proportions make the bulb inefficient. [1]

Solutions

6QuestionCalculating Power and Energy Transfer RateConcept Practice

3 marks~5 minCriterion A

A harbour crane lifts identical shipping containers, each requiring 4 500 J of work. The graph shows how the crane's power output

P

(in W) varies with the time

t

(in s) taken to complete each lift.

State the equation linking power, work done, and time. [1]

The crane completes one lift in 15 s. Calculate the power output. [1]

Explain the shape of the graph, including why the curve becomes less steep as time increases. [1]

Solutions

7QuestionEnergy Resource Comparison ChartConcept Practice

1 mark~2 minCriterion A

The diagram shows a hydroelectric dam with water stored at height

h = 45\ \text{m}

above the turbines. The reservoir holds

2.4 \times 10^9\ \text{kg}

of water.

Identify the type of energy possessed by the water stored in the reservoir. [1]

Solutions

8QuestionAdvantages and Disadvantages of Energy ResourcesConcept Practice

2 marks~3 minCriterion A

A wind farm and a coal-fired power station both generate electricity for a national grid. A student claims that one source will eventually run out while the other will not.

State which energy source is renewable and which is non-renewable. [1]

Explain one environmental disadvantage of using coal rather than wind to generate electricity. [1]

Solutions

9QuestionEnergy Resource Comparison ChartConcept Practice

2 marks~3 minCriterion D

A rural village in sub-Saharan Africa installs a solar farm to replace diesel generators as its primary electricity source.

Identify one specific way the village uses the electricity generated by the solar farm. [1]

Explain two distinct societal impacts — from different categories — that this solar farm is likely to have on the village community. [1]

Solutions

10QuestionHydraulic SystemsConcept Practice

2 marks~3 minCriterion A

A hydraulic lift is used in a car repair workshop to raise vehicles. A simplified diagram of the system is provided, showing two pistons connected by a sealed chamber. The components are unlabelled.

Identify the following components by writing the correct term next to the arrow pointing to each part:

Input piston [1]

Output piston [1]

Solutions

11QuestionComparing All Three Modes of Heat TransferAssessment Practice

12 marks~18 minCriterion A

Three setups are heated by identical electric heating elements for 10 minutes. Setup A is a solid aluminium rod, Setup B is a beaker containing 200 g of water, and Setup C is a sealed vacuum flask containing 200 g of air. A temperature–time graph is provided showing three distinct curves labelled P, Q, and R.

Specific heat capacity of water:

c = 4180 \ \text{J kg}^{-1} \text{K}^{-1}

Specific heat capacity of aluminium:

c = 900 \ \text{J kg}^{-1} \text{K}^{-1}

Identify which curve (P, Q, or R) corresponds to each setup (A, B, C). Justify your answer by linking the shape of each curve to the dominant mode of heat transfer in that setup. [4]

Explain how conduction in the aluminium rod and convection in the water beaker produce the temperature–time curves you identified in part (a). [4]

Analyse why the water in Setup B heats more slowly than the aluminium in Setup A, even though convection distributes thermal energy efficiently throughout the water. Use the specific heat capacity values provided to support your answer. [4]

Solutions

12QuestionRadiation and Emission of Infrared EnergyAssessment Practice

5 marks~8 minCriterion B

A student heats a small metal cube and records its surface temperature

T

and the power

P

radiated from its surface.

T

(K): 300, 400, 500, 600

P

(W): 8.1, 25.6, 62.5, 129.6

Calculate

\dfrac{P}{T^4}

for each data point. [2]

Deduce the relationship between

T

and

P

for this cube, expressing it as an equation. [2]

The student claims the cube will radiate more than 250 W at 700 K. Evaluate this claim using your equation from part (b). [1]

Solutions

13QuestionConduction in Solids and Thermal ConductorsAssessment Practice

4 marks~6 minCriterion D

A house wall consists of four layers: outer brick, an air cavity filled with insulation, inner brick, and plasterboard. Three insulation materials are available:

Fiberglass: thermal conductivity

k = 0.040 \ \text{W m}^{-1}\text{K}^{-1}

, low cost, energy-intensive to manufacture.
Spray foam:

k = 0.025 \ \text{W m}^{-1}\text{K}^{-1}

, highest cost, seals air gaps completely, uses ozone-depleting blowing agents.
Recycled denim:

k = 0.037 \ \text{W m}^{-1}\text{K}^{-1}

, moderate cost, made from post-consumer waste.

Explain how thermal conductivity determines the rate of heat transfer through the insulation layer. [1]

Using the

k

-values, explain which material reduces heat transfer most effectively and why eliminating air gaps further improves insulation. [2]

Evaluate the trade-offs between spray foam and recycled denim, considering environmental impact, cost, and long-term energy savings. [1]

Solutions

14QuestionConvection in Liquids and GasesAssessment Practice

12 marks~18 minCriterion C

A student heats a beaker of water using a hot plate placed beneath the beaker. Three temperature probes are positioned at different depths:

Probe A: near the bottom, close to the hot plate
Probe B: in the middle of the water
Probe C: near the top surface

Over 10 minutes, the recorded temperature changes are:

Probe A: 20 °C → 70 °C (rapid increase)
Probe B: 20 °C → 50 °C (steady increase)
Probe C: 20 °C → 30 °C (slow increase)

Analyse the temperature–time data for all three probes. In your answer, compare the rates of temperature increase and describe the overall trend shown by the data. [3]

Explain how the temperature differences observed between the probes produce convection currents in the water. In your answer, refer to particle motion, density changes, and the resulting movement of warm and cool water. [4]

A student claims: "Probe C will eventually reach the same temperature as Probe A if heating continues long enough, so the position of the probe does not matter." Evaluate this claim. In your answer, consider the role of convection, the position of the heat source, and any factors that would limit the temperature at Probe C. [5]

Solutions

15QuestionInsulation Techniques and Practical ApplicationsAssessment Practice

12 marks~18 minCriterion C

Three identical model houses were built with different wall insulation materials: Material A, Material B, and Material C. Each house was heated to 30 °C and then allowed to cool in a room held at a constant 10 °C. The temperature inside each house was recorded over 60 minutes and is shown in the graph below.

Analyse the graph to identify which material produced the slowest rate of temperature decrease. Support your answer with data from the graph. [2]

Explain how the rate of temperature decrease is related to the thermal conductivity of an insulation material. [3]

A homeowner claims that Material C is the best insulator but argues that insulation material is the only factor that matters when reducing heat loss from a house. Evaluate this claim. [4]

The homeowner is also considering the thickness of the insulation layer. Explain how doubling the thickness of Material C would affect the rate of heat loss through the walls. [3]

Solutions

16QuestionConvection in Liquids and GasesAssessment Practice

12 marks~18 minCriterion A

A room is heated by a radiator placed near the floor beneath a window. A thermal camera reveals the following: air near the radiator warms first; warm air rises toward the ceiling; cooler air near the window sinks toward the floor; a circulating current of air forms throughout the room.

Explain why radiators are placed near the floor rather than near the ceiling. [2]

Describe how convection currents transfer thermal energy around the room. In your answer, refer to how the air near the radiator changes, how density is involved, and how warm and cool air move. [4]

Explain why convection does not occur in solids. Use particle theory in your answer. [2]

Identify one real-world application of convection currents other than room heating. Explain how convection is involved. [2]

A student states: "Heating a room mainly by convection is more effective than heating it only by conduction." Evaluate this statement, considering how thermal energy spreads through the room and one limitation of convection heating. [2]

Solutions

17QuestionDesigning Energy-Efficient SystemsAssessment Practice

3 marks~5 minCriterion A

A bar chart shows the percentage of energy lost as heat in transformer cores made from three materials: iron loses the most, silicon steel loses a moderate amount, and ferrite loses the least.

State the primary mechanism by which energy is lost as heat in a transformer core. [1]

Explain how the electrical conductivity of a core material determines the magnitude of this energy loss. [1]

Using the relationship

P = I^2R

, discuss why the observed pattern of energy loss (iron > silicon steel > ferrite) is consistent with the electrical properties of these three materials. [1]

Solutions

18QuestionIdentifying Input and Output Energy FormsAssessment Practice

12 marks~18 minCriterion B

A toaster's heating element converts electrical energy into thermal energy. The table below shows measurements taken at three power settings.

Toaster setting	Low, Medium, High
Electrical energy input (J)	500, 750, 1000
Thermal energy output (J)	400, 600, 700

The cost of electricity is 0.20 dollars per 1000 J.

\text{Efficiency} = \frac{\text{useful energy output}}{\text{total energy input}} \times 100

Calculate the efficiency of the toaster at each of the three settings. [3]

Deduce what the data suggest about how energy losses change as the toaster setting increases. [3]

Analyse why operating the toaster at the High setting is less energy-efficient than at the Low setting, identifying the dominant form of energy loss and explaining the physical mechanism by which that loss increases at higher power. [6]

Solutions

19QuestionBattery to Mechanical Energy ConversionAssessment Practice

6 marks~9 minCriterion C

A student tests a battery-powered toy car using AAA, AA, and C cells at different voltages. For each battery type, three trials are conducted and the average distance travelled on a flat surface is recorded. The graph below shows average distance travelled (m) against battery voltage (V) for each battery size.

Interpret the graph by identifying two distinct patterns in the data. [2]

Explain how battery size affects the energy available to drive the toy car, linking chemical energy storage to the observed distances. [2]

A D-cell battery has a voltage of 1.5 V and a larger physical size than a C cell. Evaluate whether the toy car would travel further with the D cell than with a C cell at the same voltage, and discuss one factor other than battery size or voltage that could limit this outcome. [2]

Solutions

20QuestionDesigning Energy-Efficient SystemsAssessment Practice

2 marks~3 minCriterion C

An incandescent light bulb contains a thin tungsten filament. When the bulb is switched on, electrical current passes through the filament. The filament has a resistance of approximately 140 Ω at operating temperature, and the bulb is rated at 60 W.

Explain the primary energy transformation occurring in the filament. [1]

A student claims the bulb is an inefficient device because most input energy does not serve its intended purpose. Justify this claim using the concept of energy transformation. [1]

Solutions

21QuestionBattery to Mechanical Energy ConversionAssessment Practice

3 marks~5 minCriterion A

A toy car's electric motor converts electrical energy into kinetic energy. A student varies the battery voltage from 1.0 V to 3.0 V and records the car's speed, obtaining a straight-line graph through the origin: speed increases proportionally with voltage.

State the complete energy transformation sequence occurring in the motor as the car accelerates. [1]

Using

P = VI

and

V = IR

, explain why increasing the battery voltage causes greater current to flow and therefore greater power to be delivered to the motor. [1]

The graph is linear but does not pass through the origin in a real motor. Explain one reason why the car only begins moving above a threshold voltage. [1]

Solutions

22QuestionDesigning Energy-Efficient SystemsAssessment Practice

10 marks~15 minCriterion D

A school is replacing 200 incandescent bulbs (60 W each) with LED bulbs (9 W each). The school operates lighting for 8 hours per day, 200 days per year. Electricity costs 0.15 dollars per kWh. Each incandescent bulb lasts 1 000 hours; each LED lasts 25 000 hours. LED bulbs contain trace amounts of heavy metals including lead and arsenic.

State the annual energy saving, in kWh, achieved by replacing all 200 bulbs with LEDs. [2]

Analyse the economic case for the school investing in LED bulbs, using your answer to (a) and the lifespan data above. [4]

Evaluate the overall environmental impact of the school's switch to LED lighting. [4]

Solutions

23QuestionBattery to Mechanical Energy ConversionAssessment Practice

12 marks~18 minCriterion D

A company is developing an electric scooter powered by a lithium-ion battery. The company claims it is more environmentally friendly than a gasoline scooter. Both scooters travel 10 000 km per year for 5 years. The electric scooter uses 0.1 kWh per km and requires a new battery every 2 years; each battery requires 500 kWh to manufacture. The gasoline scooter uses 0.05 L per km, with a fuel energy density of 10 kWh per litre.

Describe one environmental impact of mining lithium or cobalt for batteries and explain how it harms the environment. [2]

Using the data above, calculate the total energy used by each scooter over 5 years, including battery manufacturing for the electric scooter. State which scooter uses less total energy. [4]

Evaluate the claim that the electric scooter is more environmentally friendly than the gasoline scooter. In your answer, identify one ethical concern related to battery material sourcing, suggest one company response, and justify whether the overall case for the electric scooter is convincing. [6]

Solutions

24QuestionEnergy Flow in SystemsAssessment Practice

12 marks~18 minCriterion B

A coal-fired power plant burns coal to generate electrical energy. Energy is lost as heat during the process. The graph below shows electrical energy output against energy input over one year.

Energy Input (

\times 10^9

J): 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

Electrical Energy Output (

\times 10^9

J): 0, 0.4, 0.8, 1.2, 1.6, 2.0, 2.4, 2.8, 3.2, 3.6, 4.0

State the formula for efficiency. [1]

Use the graph to calculate the efficiency of the power plant at an energy input of

6 \times 10^9

J. Show your working. [3]

The plant operates at a higher load, with an energy input of

9 \times 10^9

J. Calculate the heat energy lost at this input and deduce whether the fraction of energy lost has changed compared to your result in part (b). [4]

Analyse the graph to evaluate whether the efficiency of the power plant is constant across all operating levels. Justify your conclusion using at least two data points not used in parts (b) or (c). [4]

Solutions

25QuestionDifferent Forms of Energy Kinetic Potential Thermal etcAssessment Practice

12 marks~18 minCriterion D

A coastal town is evaluating a proposal to build an offshore wind farm. Each turbine has a rotor swept area of 8 000 m², and at a wind speed of 12 m/s the air passing through one rotor each second has a mass of 96 000 kg. The turbines replace a coal-fired power station that burns chemical energy stored in fossil fuels.

Explain the sequence of energy transformations that occurs as wind drives a turbine to produce electricity, and calculate the maximum kinetic energy available per second from one rotor at 12 m/s. [4]

Analyse two environmental drawbacks of the wind farm, linking each drawback to a specific physical or ecological mechanism. [4]

Evaluate whether the wind farm is a sustainable and ethical solution for the town, weighing the energy and environmental evidence from parts (a) and (b) against each other. [4]

Solutions

26QuestionDifferent Forms of Energy Kinetic Potential Thermal etcAssessment Practice

12 marks~18 minCriterion C

A pendulum bob of mass 0.20 kg is released from a height of 0.45 m above its lowest point. A motion sensor records position and velocity every 0.05 s over one complete swing. Students calculate

E_p = mgh

and

E_k = \frac{1}{2}mv^2

at each instant and plot

E_p

E_k

, and total mechanical energy

E_T = E_p + E_k

against time. The graph shows

E_p

and

E_k

varying smoothly in opposition, while

E_T

decreases gradually from 0.88 J to 0.79 J over the swing.

Describe the energy transformations that occur during one complete swing of the pendulum. [3]

Analyse the graph to determine whether the data supports the principle of conservation of energy. [4]

Evaluate the experimental design, identifying limitations and suggesting improvements that would better validate the energy conservation model. [5]

Solutions

27QuestionDifferent Forms of Energy Kinetic Potential Thermal etcAssessment Practice

7 marks~11 minCriterion D

A wind farm supplies electricity to a small town. Each turbine has a rotor diameter of 80 m and operates at an efficiency of 35%. At a wind speed of 12 m/s, the mass of air passing through one turbine per second is 72 000 kg.

State the sequence of energy conversions that occur from moving air to electricity delivered to homes. [2]

The kinetic energy of air passing through one turbine per second is 5 184 000 J. Calculate the electrical power output of one turbine at this wind speed. [2]

Evaluate the suitability of this wind farm as the town's sole electricity source, considering both the variability of wind and one additional factor of your choice. [3]

Solutions

28QuestionEnergy Transformations and Real-Life ExamplesAssessment Practice

10 marks~15 minCriterion D

A community is considering building a wind farm along a known migratory corridor for several bird species. Wind turbines transform the kinetic energy of wind into electrical energy, providing a renewable alternative to fossil fuels. Environmental groups warn that spinning blades pose a direct collision risk to birds, and that turbine noise may alter migration behaviour. The community must weigh the long-term climate benefits of renewable energy against immediate, localised harm to wildlife.

Discuss two potential negative environmental impacts the wind farm could have on migratory bird populations. [2]

Analyse the ethical tension between the benefits of renewable energy and the risks posed to wildlife, referring to both sides of the argument. [3]

Evaluate two mitigation strategies that could reduce harm to bird populations, discussing the effectiveness and limitations of each. [5]

Solutions

29QuestionDifferent Forms of Energy Kinetic Potential Thermal etcAssessment Practice

3 marks~5 minCriterion A

A roller coaster car of mass 800 kg starts from rest at point A, height 40 m above the ground. It descends to point B at ground level, then rises to point C at height 25 m. Assume no energy is lost to friction.

Calculate the gravitational potential energy of the car at point A. Use

g = 10 \text{ m s}^{-2}

. [1]

Explain how kinetic energy and gravitational potential energy change as the car moves from A to B to C. [1]

Point C is lower than point A. Analyse what this difference in height tells us about the total mechanical energy of the car in a real roller coaster, where friction acts. [1]

Solutions

30QuestionCalculating Power and Energy Transfer RateAssessment Practice

5 marks~8 minCriterion B

A cyclist travels along a flat, horizontal road. The graph below shows the cyclist's power output

P

plotted against velocity

v

. Assume all power output is used to overcome resistive forces.

From the graph, determine the cyclist's power output at

v = 6\ \text{m/s}

. [1]

Using your answer from part (a), calculate the magnitude of the resistive force acting on the cyclist at

v = 6\ \text{m/s}

. [2]

The graph shows a linear relationship between

P

and

v

, passing through the origin. Analyse what this relationship reveals about how the resistive force changes as the cyclist's velocity increases, and justify your conclusion using your result from part (b). [2]

Solutions

31QuestionUnits Joules Watts and Their ConversionsAssessment Practice

12 marks~18 minCriterion A

A student investigates how the bounce height of a tennis ball depends on its drop height. The table below shows the data collected.

Drop height $h_d$ (m)	1.00	1.50	2.00	2.50	3.00
Bounce height $h_b$ (m)	0.70	1.05	1.40	1.75	2.10

Construct a graph of bounce height against drop height, plotting all five data points and drawing a line of best fit. [2]

Deduce the relationship between

h_b

and

h_d

, expressing your answer as an equation. [3]

Justify a prediction for the bounce height when the ball is dropped from 3.50 m. [2]

In a real experiment the ball bounces several times, each time reaching a lower height, until it stops. Analyse the energy transformations occurring during this process and explain why the ball eventually stops bouncing. [5]

Solutions

32QuestionDefinition and Formula for Work DoneAssessment Practice

12 marks~18 minCriterion D

A coastal community is evaluating a proposed wind turbine farm. Each turbine blade sweeps a circular path of radius 40 m, and the average force exerted by the wind on the blades is

5.0 \times 10^{5}

N. The blades complete one full rotation every 3.0 s, and the turbine operates for 8.0 hours each day.

Calculate the work done by the wind on the turbine blades during one full rotation. [2]

Calculate the total energy transferred by the wind to one turbine in a single day of operation, and explain how this value relates to the concept of power. [4]

Evaluate the ethical considerations involved in siting the wind turbine farm in a coastal habitat, discussing the trade-offs between renewable energy generation and potential harm to local wildlife, and proposing mitigation strategies. [6]

Solutions

33QuestionImproving Efficiency in Machines and DevicesAssessment Practice

4 marks~6 minCriterion D

Low-friction coatings applied to engine pistons and cylinder walls reduce the friction force acting between moving surfaces. These coatings may contain per- and polyfluoroalkyl substances (PFAS), which are chemically persistent compounds.

Explain how reducing friction between the piston and cylinder wall improves the engine's efficiency. [1]

Explain one benefit to the engine itself of reduced friction between these surfaces. [1]

Discuss the environmental risks associated with the production, use, and disposal of PFAS-based low-friction coatings, considering chemical leaching at each stage. [2]

Solutions

34QuestionImproving Efficiency in Machines and DevicesAssessment Practice

11 marks~17 minCriterion C

An electric motor operating in an industrial facility is tested across a range of temperatures. The graph below shows how its efficiency varies with operating temperature.

The x-axis shows operating temperature (°C); the y-axis shows efficiency (%). Efficiency decreases gradually from 20 °C to 80 °C, then declines more sharply above 80 °C.

Describe the relationship between operating temperature and efficiency shown in the graph. Reference at least two distinct regions in your answer. [2]

Explain why increasing operating temperature causes the motor's efficiency to decrease. In your answer, refer to electrical resistance, wasted heat energy, and useful mechanical output. [4]

Evaluate one engineering method used to limit efficiency losses in motors that operate continuously above 80 °C. In your answer, discuss one advantage and one limitation of the method, and judge whether the method is likely to be worthwhile for an industrial operator. [5]

---

Solutions

35QuestionEfficiency = Useful Output Total Input x 100Assessment Practice

12 marks~18 minCriterion A

A student investigates the efficiency of solar panels under constant light intensity. A single panel and two identical panels connected in series and in parallel are each tested at their optimal load resistance. The wire resistance in each configuration is

R_w = 0.5\ \Omega

. Measured output values are:

Single panel — Voltage:

5.0\ \text{V}

, Current:

0.5\ \text{A}

Two in series — Voltage:

10.0\ \text{V}

, Current:

0.5\ \text{A}

Two in parallel — Voltage:

5.0\ \text{V}

, Current:

1.0\ \text{A}

Calculate the useful power output for each configuration. [3]

Deduce which configuration — series or parallel — delivers more power to the load per panel used, and explain why the values are equal or unequal. [3]

Analyse how heat losses in the wires affect the efficiency of the series and parallel configurations differently, and justify which configuration is more efficient. [6]

Solutions

36QuestionImproving Efficiency in Machines and DevicesAssessment Practice

8 marks~12 minCriterion C

A student investigates a pulley system by measuring the work input and work output for four different loads.

Load (N)	5	10	15	20
Work input (J)	20	42	65	89
Work output (J)	15	30	45	60

Calculate the efficiency of the pulley system for each load. [4]

Deduce how the efficiency of the pulley system changes as the load increases. Justify your answer with reference to the data. [2]

A student claims that redesigning the pulley with sealed, lubricated bearings and a lighter rope would increase efficiency. Evaluate this claim by identifying the energy loss mechanisms it addresses and one it does not. [2]

Solutions

37QuestionFossil Fuels and Their Environmental ImpactAssessment Practice

8 marks~12 minCriterion B

Coal is ranked by carbon content and energy density: Anthracite > Bituminous > Sub-bituminous > Lignite. Sulfur content influences SO2 emissions during combustion. The table below shows sulfur content (percentage by mass) for three coal types sampled from three mines.

Anthracite — Mine A	0.5%	Mine B: 0.6%	Mine C: 0.4%
Bituminous — Mine A	1.5%	Mine B: 1.7%	Mine C: 1.3%
Lignite — Mine A	3.0%	Mine B: 3.2%	Mine C: 2.8%

Describe the trend in sulfur content across the three coal types shown. [2]

Calculate the average sulfur content for each coal type and use these values to deduce the expected range of sulfur content for sub-bituminous coal. [3]

A power station manager claims that switching from bituminous to sub-bituminous coal will have a negligible impact on SO2 emissions. Evaluate this claim using your results from (b) and your understanding of coal combustion. [3]

Solutions

38QuestionAdvantages and Disadvantages of Energy ResourcesAssessment Practice

12 marks~18 minCriterion D

A country operates a nuclear power station for 20 years. The data below summarises its performance.

Annual electricity generation (TWh):
Years 1–10: rising from 80 TWh to 250 TWh
Years 11–20: stable between 240 TWh and 260 TWh

Additional data:
Total nuclear waste produced: 8 000 metric tons
Minor incidents (no radiation release): 15
Major incidents (radiation release): 2

Analyse the trend in annual electricity generation over the 20-year period. [2]

Identify two advantages of nuclear power and justify each using evidence from the data. [4]

Identify two disadvantages of nuclear power and justify each using evidence from the data. [4]

Evaluate the extent to which this dataset alone is sufficient to make a comprehensive judgment about nuclear power as an energy source. [2]

Solutions

39QuestionFossil Fuels and Their Environmental ImpactAssessment Practice

3 marks~5 minCriterion C

The graph below shows atmospheric

\text{CO}_2

concentration (ppm) and global average temperature (°C) from 1900 to 2020. Both quantities rise over this period.

Describe the relationship between

\text{CO}_2

concentration and global average temperature shown in the graph. [1]

Explain how

\text{CO}_2

molecules in the atmosphere interact differently with incoming solar radiation and outgoing radiation from Earth's surface. [1]

Explain how increasing

\text{CO}_2

concentration causes the temperature trend shown in the graph. [1]

Solutions

40QuestionAdvantages and Disadvantages of Energy ResourcesAssessment Practice

12 marks~18 minCriterion D

A homeowner in Iceland is considering installing solar panels. Iceland experiences up to 20 hours of darkness per winter day and an annual average solar irradiance of approximately 90 W m⁻², compared with 200 W m⁻² in southern Europe. Iceland already generates over 99% of its electricity from geothermal and hydropower sources.

State two advantages of solar panels as an electricity source. [2]

Explain the limitations of solar panel technology specifically in Iceland, including the role and cost implications of energy storage systems. [4]

Discuss the environmental impacts of solar panels across their full lifecycle: manufacturing, operation, and disposal. [3]

Evaluate whether solar panels represent a cost-effective and sustainable electricity solution for Iceland, given its climatic conditions and existing energy infrastructure. [3]

Solutions

41QuestionTypes of Renewable Energy SourcesAssessment Practice

8 marks~12 minCriterion A

A photovoltaic (PV) cell of area

0.01 \ \text{m}^2

is tested at different light intensities. A student records the electrical power output using a calibrated power meter. The results are plotted on the graph below.

Deduce the electrical power output of the PV cell at a light intensity of

600 \ \text{W/m}^2

. [2]

Calculate the efficiency of the PV cell at a light intensity of

600 \ \text{W/m}^2

, given that

\eta = \frac{P_{\text{out}}}{P_{\text{in}}}

where

P_{\text{in}} = \text{intensity} \times \text{area}

. [2]

Analyse the graph to explain how efficiency changes with increasing light intensity and evaluate one physical cause of this trend. [4]

Solutions

42QuestionHydraulic SystemsAssessment Practice

3 marks~5 minCriterion A

A hydraulic excavator uses a hydraulic arm to lift heavy loads on construction sites. The operator pushes a control lever, causing a pump to pressurize hydraulic fluid inside a sealed cylinder.

Identify the physical principle that allows pressure applied at the pump to move the excavator arm at a distant cylinder. [1]

Explain how pressure is transmitted through the hydraulic fluid to produce a larger force at the excavator arm's cylinder than the pump applies. [1]

Discuss one societal benefit and one societal drawback of using hydraulic excavators in large-scale construction. [1]

Solutions

43QuestionHydraulic SystemsAssessment Practice

4 marks~6 minCriterion C

A student builds a model hydraulic system using two syringes of different cross-sectional areas, connected by a tube filled with water. The input syringe has a cross-sectional area of 2 cm² and the output syringe has a cross-sectional area of 6 cm². A force of 10 N is applied to the input piston.

State the property of liquids that makes them suitable as the working fluid in a hydraulic system. [1]

The student replaces the water with air. Explain how this change affects pressure transmission in the system, with reference to compressibility. [2]

Evaluate the consequences of using a compressible fluid in a real hydraulic braking system. [1]

Solutions

44QuestionHydraulic SystemsAssessment Practice

12 marks~18 minCriterion B

A hydraulic lift in a car repair shop has two pistons of different areas. A mechanic applies a force to the smaller input piston; the larger output piston lifts the car. Pressure is transmitted equally throughout the fluid.

The table below shows measured values for five operating conditions.

F_{in}

(N): 100, 100, 100, 200, 200

F_{out}

(N): 500, 1000, 1500, 1000, 2000

\dfrac{A_{out}}{A_{in}}

: 5, 10, 15, 5, 10

Deduce the relationship between

F_{in}

F_{out}

, and

\dfrac{A_{out}}{A_{in}}

, and explain the physical reasoning behind it. [4]

The mechanic increases the input force to 300 N and fits a new output piston so that

\dfrac{A_{out}}{A_{in}} = 8

. Calculate the output force and explain how Pascal's principle ensures this result. [4]

A different lift has an output piston of area 0.5 m² and an area ratio

\dfrac{A_{out}}{A_{in}} = 20

. The manufacturer claims the input piston area is 0.025 m². Evaluate this claim, and explain what effect a larger input piston area would have on the force needed to lift the same load. [4]

Solutions

45QuestionHydraulic SystemsAssessment Practice

10 marks~15 minCriterion D

A hydraulic car lift in a repair shop has an input piston of radius

r_1 = 5\ \text{cm}

and an output piston of radius

r_2 = 20\ \text{cm}

. The pistons are connected by hydraulic fluid. A technician applies a force to the input piston to raise a car.

A force of 150 N is applied to the input piston. Calculate the pressure transmitted to the hydraulic fluid. [2]

Deduce the pressure acting on the output piston, and calculate the force the output piston exerts. [4]

The car weighs 14 400 N. Evaluate whether a single technician, who can exert a maximum force of 900 N, is able to lift the car using this hydraulic system. Justify your answer with calculations. [4]

---

Solutions

46QuestionPressure in Liquids / GasesAssessment Practice

12 marks~18 minCriterion D

A small town is debating whether to permit hydraulic fracturing (fracking) for natural gas extraction. Fracking involves pumping fluid at very high pressure into shale rock formations deep underground. The pressure fractures the rock, opening pathways through which trapped natural gas can escape and be collected. Local residents, energy companies, and environmental groups each hold different views on whether the town should proceed.

Explain how the physics of pressure in fluids makes fracking work. [2]

Identify one economic benefit and one environmental risk of fracking for the town, linking each to the high-pressure fluid injection process. [4]

Evaluate whether conducting an environmental impact assessment (EIA) before fracking begins is sufficient to guarantee the long-term safety and sustainability of the operation. [6]

Solutions

47QuestionHydraulic SystemsAssessment Practice

12 marks~18 minCriterion A

A hydraulic jack lifts a car using an output piston of area

A_{output} = 0.20 \text{ m}^2

. A student records output force and input force for three different input piston areas, producing three straight lines (A, B, C) through the origin on the graph provided. The input piston area for line A is

0.010 \text{ m}^2

Deduce the pressure of the hydraulic fluid from line A. Show all working. [3]

Calculate the input piston areas for lines B and C, using their slopes from the graph. Show all working. [4]

Analyse how all three lines on the graph would change if the output piston area were doubled to

0.40 \text{ m}^2

, while all input piston areas remain unchanged. [5]

Solutions

48QuestionHydraulic SystemsAssessment Practice

12 marks~18 minCriterion D

Hydraulic brakes are used in most modern cars. A simplified system consists of a master cylinder (piston area

A_m = 5.0 \text{ cm}^2

) connected by brake fluid to a wheel cylinder (piston area

A_w = 20 \text{ cm}^2

). A driver applies a force of

150 \text{ N}

to the master piston.

State Pascal's principle and use it to calculate the force exerted by the wheel cylinder piston on the brake pad. [3]

Explain how the incompressibility of brake fluid and the difference in piston areas together make hydraulic brakes more effective than a mechanical cable system. [3]

Analyse two limitations of hydraulic brake systems, considering both safety and environmental impact. For each limitation, explain the consequence and suggest one way it could be mitigated. [6]

Solutions