Revision for Chapter 15

1. Electricity generated from the difference in the height of water at high tide and low tide is called ___ energy.
6. ___ refers to plant and animal material.
8. Fossil fuels cannot be replaced and are ___.
10. Electricity produced from moving water is called ___.
12. Michelle who is reading a book on the bed is doing __ work, in scientific terms.
14. If a lady carries a box and travel a further distance, she does ___ work.
15. The ability to do work is termed as ___.

1. Energy is ___ when work is done.
2. If a man carries a lighter bag and travels a short distance, he does ___ work.
3. Coal and natural gas are ___ fuels.
4. The ___ that comes from the earth is used to generate electricity, using geothermal energy.
5. Burning fossil fuel causes air ___.
7. ___ contributes to global warming and soil erosion.
9. There are ___ conditions for work to be done.
11. If the total amount of energy before and after the change is exactly the same, we say that energy is ___.
13. The SI unit for work done is ___.