| A | B |
|---|
| Work | symbol W; unit J (Joules) |
| Power | symbol P; unit W (Watts) |
| Time | symbol t; units s (seconds) |
| Mega- | means x by a million (1000000) |
| Micro- | means divide by a million |
| Milli- | means divide by a thousand |
| Centi- | means divide by 100 |
| Deci- | means divide by 10 |
| Nano- | means divide by a billion (a billion has nine zeros) |
| Kilo- | means x by a thousand |
| Energy | symbol E; unit J (Joules) |
| Distance | symbol is d; measured in m (metres) |
| Height | symbol is h; measured in m (metres) |
| Wavelength | symbol is lambda; measured in m (metres) |
| Frequency | symbol is a long f; measured in Hz (hertz) |
| Speed | symbol is v; measured in metres per second |
