The physics
Gravitational potential energy is stored height: mass × gravity × elevation. Lift something up and you bank energy; let it fall and the bank pays out as motion, heat or electricity.
Potential energy of a 2 kg book on a 2 m shelf
Answer: potential energy = 39.2 J (in kilowatt-hours 1.090e-5 kWh, in food calories 0.009 kcal).
What we know
- Mass: 2 kg
- Height: 2 m
Step by step
- Given
- m = 2 kg, h = 2 m
- Formula
- PE = m × g × h
- Substitute
- PE = 2 × 9.80665 × 2
- Result
- PE = 39.2 J
All results
| Potential energy | 39.2 J |
|---|---|
| In kilowatt-hours | 1.090e-5 kWh |
| In food calories | 0.009 kcal |
Open the potential energy calculator with these numbers → and change any of them.