Question 7

Gap-fill exercise

Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!

The Law of Conservation of Energy states that energy is neither nor . It is turned from one form to another. This means that all can be accounted for.

When we use energy we have to put in energy than we get out as useful work. This means that some energy is . The wasted energy is . We can sometimes get useful work out of this wasted energy. However the further down the energy chain we go, the this becomes.

All energy ends up as heat. It is very hard to get useful energy from this. When we use energy, we end up warming up the .

It is important that we reduce the waste of energy. A more engine means less wasted heat. We need to think carefully about how we use fuels.