Resources of Materials & Energy (AQA GCSE Combined Science: Synergy: Physical Sciences): Exam Questions

Figure 5 shows a person driving a bumper car at a theme park.

The mass of the bumper car and driver is 360 kg.

The bumper car moves with a speed of 1.50 m/s.

Calculate the kinetic energy of the bumper car and driver.

Use the equation:

$\text{kinetic energy}=0.5\times \text{mass}\times (\text{speed}{)}^2$

Use the Physics Equations Sheet to answer this question.

Write down the equation which links efficiency, total power input and useful power output.

The motor of the bumper car has an efficiency of 0.80

The total power input to the motor is 220 W.

Calculate the useful power output of the motor.

Another bumper car slows down and stops to avoid a collision.

Complete the sentences.

Choose answers from the box.

As the bumper car slows down, its kinetic energy _________ .

As the bumper car slows down, the thermal energy of the surroundings __________ .

The LED bulb wastes energy as thermal energy.

How does the thermal energy affect the temperature of its surroundings?

The bumper car motor has an efficiency of 80%.

The useful power output of the motor is 220 W.

Calculate the total power input to the motor.

Use the Physics Equations Sheet.

This question is about the extraction of metals.

Name the process that uses bacteria to extract metals.

Iron can be extracted from iron oxide using carbon.

The word equation for the reaction is:

iron oxide + carbon → iron + carbon dioxide

Explain why this reaction is both oxidation and reduction.

Give one reason why some metals cannot be extracted from their oxides using carbon.

Aluminium is manufactured by the electrolysis of a molten mixture of aluminium oxide and cryolite.

Explain why cryolite is used.

Aluminium is produced at the negative electrode.

Complete the half equation for the reaction.

You should balance the equation.

$\mathrm{A}{\mathrm{l}}^{3+}+\text{\_\_\_\_\_\_\_\_\_\_\_\_}\to \text{\_\_\_\_\_\_\_\_\_\_\_\_}$

This question is about life cycle assessments (LCAs).

Shopping bags can be made from paper or plastic.

Each type of bag can carry the same volume of shopping.

Evaluate the use of paper compared with the use of plastic for shopping bags.

Use Table 1 and your knowledge and understanding of LCAs.

This question is about metal extraction and recycling.

Most metals are found in the Earth as metal compounds.

Why is gold found in the Earth as the metal itself?

How is aluminium extracted from aluminium compounds?

Tick (✓) one box.

Iron oxide is heated with carbon to produce iron and carbon dioxide.

The word equation for the reaction is:

iron oxide + carbon → iron + carbon dioxide

Which substance is oxidised in the reaction?

Iron is used to make steel. Scrap steel can be recycled.

Give two environmental advantages of recycling scrap steel instead of making new steel from iron.

1 .______________________________________________________

2 .______________________________________________________

Table 3 shows information about scrap steel in one year.

Table 3

Calculate the percentage (%) of scrap steel that was recycled in one year.

Percentage =__________________ %

Figure 5 shows metal food and drink cans.

The metal cans are made from steel or aluminium.

Which property of steel means that steel can be separated from aluminium at a recycling centre?

The brakes are made of a material with a high thermal conductivity.

Explain what is meant by 'high thermal conductivity'.

This question is about metal extraction.

Copper compounds can be extracted from low-grade copper ores using:

• plants

• bacteria.

Name the process that uses plants to extract copper compounds from low-grade copper ores.

Name the process that uses bacteria to extract copper compounds from low-grade copper ores.

Why are processes using plants and bacteria now used to extract copper compounds from low-grade copper ores?

Give one advantage of extracting copper compounds using plants and bacteria rather than using traditional methods.

Aluminium is extracted by the electrolysis of a molten mixture of aluminium oxide and cryolite.

Explain why the electrolyte used is a mixture of aluminium oxide and cryolite.

Do not refer to cost in your answer.

Oxygen is produced at the positive electrodes.

Explain why the positive electrodes must be continually replaced.

This question is about life cycle assessments (LCAs).

LCAs assess the environmental impact of a product.

An LCA has four stages.

Complete the sentences.

Choose answers from the box.

The first stage of an LCA assesses how raw materials are _____________ .

The final stage of an LCA assesses how the product is _______________.

Figure 4 shows the environmental impact of the use of energy, materials and bleach during the production of two different shirts.

Draw one line from each statement to the cause of the environmental impact.

Use Figure 4.

The total environmental impact of producing shirt A is 4.0 arbitrary units.

Determine the percentage of the total environmental impact of producing shirt A that is caused by energy use.

You should:

• give the environmental impact caused by energy use for shirt A

• calculate the percentage of the total environmental impact caused by energy use for shirt A.

Use Figure 4.

Environmental impact = __________________ arbitrary units

Percentage = _______________ %

LCAs should be peer reviewed by independent scientists.

Give one reason why the peer review should be independent.

Energy resources are renewable or non-renewable.

Which two of the following energy resources are renewable?

Tick (✓) two boxes.

Figure 5 shows wind turbines in the countryside.

What are two effects on the environment of using wind turbines to generate electricity?

Tick (✓) two boxes.

Figure 6 shows a wind turbine.

The useful power output of the generator in the wind turbine is 144 000 W.

The efficiency of the wind turbine is 0.30.

Calculate the total power input to the wind turbine.

Use the equation:

$\mathrm{total}\mathrm{power}\mathrm{input}=\frac{\mathrm{useful}\mathrm{power}\mathrm{output}}{\mathrm{efficiency}}$

Total power input = ________________ W

Use the Physics Equations Sheet to answer this question.

Which equation links current, potential difference and power?

Tick (✓) one box.

Figure 7 shows how the National Grid links the wind turbine to consumers.

The step-up transformer increases the potential difference and decreases the current.

What effect does decreasing the current have on the energy loss from the power cables?

Tick (✓) one box.

What is the function of the step-down transformer in Figure 7?

Tick (✓) one box.

This question is about life cycle assessments (LCAs).

LCAs assess the environmental impact of different processes during the life cycle of a product.

Table 2 shows values for the environmental impact of three processes during the production of two shirts.

Table 2

The environmental impacts were measured in different units.

The measurements were converted to values with the same units.

These units are known as equivalent units.

Give one reason why equivalent units are used in LCAs.

Evaluate the environmental impact of producing shirt A compared with producing shirt B.

Use Table 2.

Use calculations in your answer.

Peer reviews are used to check LCAs.

Why should an independent scientist be used to peer review an LCA?

Some LCAs assess the environmental impact of metal extraction.

Name the biological methods of metal extraction that use:

• bacteria

• plants.

Nuclear power stations and coal power stations have an environmental impact.

Compare the environmental impact of generating electricity using these two types of power station.

In a power station 900 MJ of thermal energy were released by burning natural gas.

Write down the equation that links efficiency, useful input energy transfer and useful output energy transfer.

In a power station 900 MJ of thermal energy were released by burning natural gas.

Only 405 MJ was generated.

Calculate the efficiency of this energy transfer.

Efficiency = ________________

A student investigates rolling a marble down a track.

Figure 1 shows how he sets up the investigation .

Figure 1

The student lets go of the marble from different heights and records:

• the height from which he drops the marble (the drop height)

• the height the marble rolls up the other side (the roll height).

What force causes the marble to fall down the track?

Tick (✓) one box.

What is one variable the student should control in the investigation?

Tick (✓) one box.

Table 1 shows the student's results.

Table 1

What is the independent variable in the investigation?

Tick (✓) one box.

Calculate the mean roll height of the marble when it is dropped from 40 cm.

Mean roll height = cm

The student calculated the mean roll height for a drop height of 60 cm.

He did not include the result for Test 2 in his calculation.

Why did the student leave out the result for Test 2?

Describe how the drop height of the marble affects the roll height.

Why does the marble never roll up to the same height the student drops it from?

Table 5 gives some information about four hydrocarbons.

Table 5

What are two correct statements about the four compounds?

Tick (✓) two boxes.

Poly(ethene) is a polymer made from ethene. Poly(ethene) is used to make plastic bags.

Table 6 is from a life cycle assessment comparing paper bags and plastic bags.

Table 6

Evaluate which type of bag is more environmentally friendly.

Use data from Table 6 and your own knowledge to support your answer.

Steel is an alloy of iron. Steel is used to make cars.

After its useful life a car is taken to a scrapyard for recycling.

Suggest four benefits of recycling a car body.

Electricity in the UK is generated in many ways.

Figure 7 shows an undersea turbine.

The undersea turbine uses tidal energy to generate electricity.

Figure 7

(image of an undersea turbine not reproduced here due to third party copyright restrictions).

The undersea turbine uses tidal energy to generate electricity.

What is the original source of energy for tidal power schemes?

Explain two advantages of using undersea tidal turbines to generate electricity rather than burning fossil fuels.

Some power stations burn wood instead of fossil fuels to generate electricity.

A coal-burning power station burns 6 million tonnes of coal per year.

Coal has an average energy value of 29.25 MJ per kg.

Wood chip from willow trees has an energy value of 13 MJ per kg.

A hectare of agricultural land can produce 9 tonnes of dry willow wood per year.

If this power station burned dry willow wood instead of coal, how much agricultural land would be needed to grow the willow?

Amount of land needed = hectares

Table 3 shows the carbon dioxide emissions of four fuels used to generate electricity.

Table 3

Direct CO₂ emissions are the amounts of carbon dioxide released when the fuel is burned.

Lifecycle CO₂ emissions are the total amount of carbon dioxide released during all stages from fuel extraction to when the fuel has been used.

Use the data from Table 3 to explain why wood is considered to be a low carbon dioxide emitting fuel.

Read the information about production of copper.

• World demand for copper in 2014 was about 22 million tonnes.

• World reserves of copper are about 700 million tonnes.

• Most of the copper today is obtained from copper ores. The ores are mined.

• Copper ore is heated in a furnace to produce copper sulfide. The furnace is heated by burning fossil fuels. Air is blown through the hot copper sulfide to produce copper and sulfur dioxide.

• Some copper is extracted from low-grade ores by phytomining. Phytomining uses plants to absorb copper compounds. The plants are burned and copper is extracted from the ashes.

A scientist stated:

'more copper should be extracted by phytomining.'

Use the information to justify the scientist's statement.