Table of Contents
Gravitational mass by a spring balance
In a spring balance, the gravitational force on a body stretches the spring and we measure the elongation of the spring. The elongation depends on gravitational force which, in turn, is proportional to the gravitational mass of the body. Thus, the elongation of the spring gives a measure of the gravitational mass. For this we first calibrate the spring balance by using standard masses and measuring the elongations.
The calibration of spring balance and the mass measurement should be done at same place because the value of g varies from place to place.
Orders of magnitude of mass
| S.No. | Object | Mass (kg) |
| 1. | Electron | 10-30 |
| 2. | Proton | 10-27 |
| 3. | Uranium atom | 10-25 |
| 4. | Cell | 10-10 |
| 5. | Dust particle | 10-9 |
| 6. | Rain drop | 10-6 |
| 7. | Mosquito | 10-5 |
| 8. | Grape | 10-3 |
| 9. | Man | 102 |
| 10. | Automobile | 103 |
| 11. | Ship | 105 |
| 12. | Moon | 1023 |
| 13. | Earth | 1025 |
| 14. | Milkyway | 1041 |
| 15. | Observable universe | 1055 |