A Small but Fundamental Unit
One joule is the energy used when a force of one newton moves an object one meter. It's a small amount — lifting an apple one meter takes about 1 joule. Everyday energies are therefore in thousands or millions of joules.
Relationships
1 food calorie (kcal) = 4,184 joules. 1 kilowatt-hour = 3,600,000 joules. 1 BTU ≈ 1,055 joules. All are fixed conversions because they measure the same physical quantity.
Reference
| Quantity | Joules |
|---|---|
| Lift an apple 1 m | 1 |
| 1 food calorie (kcal) | 4,184 |
| 1 kWh | 3,600,000 |
| 1 BTU | 1,055 |