OCR Gateway GCSE Physics A topics P7 Energy and P8 Global challenges overview quiz quiz

The total energy of a closed system is always steadily increasing over time

Energy is completely destroyed whenever it is wasted or dissipated

Energy cannot be created or destroyed, only transferred between stores

Energy can be created from nothing by a motor or another machine

Work done equals the force divided by the total distance moved by the object

Work done equals the mass of the object multiplied by its speed

Work done equals the power multiplied by the distance that is moved

Work done equals force times distance moved in the direction of the force

It increases four times

It doubles

It stays the same

It increases three times

The total amount of energy that is stored within a system

The rate of transferring energy or doing work, in watts

The size of the force that is applied to an object

The total distance that an object moves in one second

Wasted energy output divided by total energy input

Total energy input divided by useful output

Useful energy output divided by total energy input

Useful output times total input

Coal

Natural gas

Uranium (nuclear fuel)

Wind

For a given power, high voltage means low current, and the heating loss in the cables (proportional to current squared) is then much smaller

High voltage electricity is much safer to touch and handle than low voltage is

High voltage electricity travels much faster along the transmission cables than low voltage electricity does, so it reaches homes and factories far more quickly than before

Transformers in the grid will only ever work properly at very low voltages

The braking distance on its own, with nothing else added

Thinking distance plus braking distance

The thinking distance on its own, with nothing else added

The distance the vehicle travels in just one single second

It reduces the overall change in momentum of the car and its occupants during the whole of the crash

It makes the whole car much heavier so that it is harder to stop

It increases the time taken to stop, so for the same change in momentum the force is smaller

It speeds the stop up so the whole crash is over much more quickly

The distant galaxies are slowly getting hotter and hotter over a very long time, which is what stretches their light out towards the red end

The galaxies themselves are gradually changing their actual colour to red

The galaxies are all moving towards us and the rest of the Milky Way

The galaxies are moving away from us, and more distant ones move away faster, showing the universe is expanding