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What is solar power?
Solar Power is using the energy from the sun to generate electricity.
Explain why places near the equator generally experience less seasonal temperature variation than places far from the equator.
Places near the equator receive relatively direct sunlight throughout the year, so the amount of solar energy they receive changes less with the seasons.
What does the term radioactive mean?
Something that gives off nuclear energy.
A battery-powered torch is switched on. Describe the energy changes that take place.
Chemical energy in the battery changes into electrical energy, which is then converted into light energy and thermal energy.
A learner notices that warm air rises inside a room. Explain why this happens.
Warm air expands, becomes less dense and rises, while cooler, denser air sinks. This movement transfers heat by convection.
Explain how the Moon's gravitational force influences ocean tides.
The Moon's gravity pulls on Earth's ocean water, contributing to the formation of high tides. As Earth rotates, coastal areas experience changes in water levels.
Why do people on Earth usually see the same side of the Moon?
The Moon takes approximately the same amount of time to rotate on its axis as it takes to orbit Earth, so the same side generally faces Earth.
Explain the difference between useful energy and wasted energy when using an electric kettle.
Useful energy heats the water. Wasted energy is transferred to the surroundings, for example as unwanted heat and sound.
Name 4 non-renewable sources of energy
Coal , oil , natural gas, uranium, diesel, petrol
A machine receives 100 J of energy and transfers 65 J into useful energy. Calculate the amount of wasted energy.
Wasted energy = Total energy − Useful energy
= 100 J − 65 J
= 35 J
A flask has a layer of insulating material around it. Explain how this material helps keep a drink hot.
The insulating material reduces heat transfer to the surroundings, slowing the cooling of the drink.
Explain why a metal spoon becomes hot when left in a pot of boiling water.
Heat is transferred through the metal spoon by conduction from the hot end to the cooler end.
Describe how fossil fuels form.
Fossil fuels form from the remains of ancient organisms that are buried and changed by heat and pressure over millions of years.
A learner claims that summer occurs because Earth is closer to the Sun. Explain why this statement is incorrect.
Seasons are mainly caused by Earth's axial tilt, which changes the angle of sunlight and the length of daylight in each hemisphere. Earth's distance from the Sun is not the main cause.
Explain why different parts of Earth experience different seasons at the same time.
Earth’s axis is tilted. When one hemisphere tilts towards the Sun, it receives more direct sunlight and generally has longer days, while the opposite hemisphere receives less direct sunlight and has shorter days.
Explain the difference between spring tides and neap tides.
Spring tides occur when the Sun, Earth and Moon are aligned, producing a larger tidal range. Neap tides occur when the Sun and Moon are positioned at approximately right angles relative to Earth, producing a smaller tidal range.
Give two advantages of using hydo power
Renewable energy source: Hydropower uses flowing water, which is naturally replenished.
Low pollution: It produces electricity with very little air pollution during operation.
Explain why burning large amounts of coal contributes to climate change.
Burning coal releases carbon dioxide, a greenhouse gas that traps heat in Earth's atmosphere and contributes to global warming.
What is ETHANOL
A biofuel which which can be added to petrol or used on its own . made from sugar cane.
How might organisms living between the high-tide and low-tide marks survive when the sea moves away from them?
They may hide in rock pools or crevices, attach themselves firmly to rocks and retain moisture to prevent drying out.
Why can the Sun warm the Earth even though space contains very little matter?
Heat travels from the Sun to Earth by radiation, which does not require a medium.
What is a biofuel, and give one example of a material that can be used to produce it.
A biofuel is a fuel made from biological material. Examples include ethanol made from sugarcane and biodiesel made from vegetable oils.
Distinguish between Earth's rotation and revolution.
Rotation is Earth's spinning on its axis and takes approximately 24 hours, causing day and night. Revolution is Earth's movement around the Sun and takes approximately 365¼ days.
xplain the difference between renewable and non-renewable energy resources. Give one example of each.
Renewable resources are naturally replenished, such as sunlight. Non-renewable resources are finite and take extremely long periods to form, such as coal.
What is a system?
A system is something which is m ade from two or more parts that work together.