The Apple and the Moon I
Is Newton’s Gravitation Force Law really “universal”? Does the same force law describe apples falling to the Earth and the Moon’s orbit about the Earth? Can we predict the acceleration due to gravity on the surface of the Earth from the Period & Radius of the Moon’s orbit?
- Acceleration of the moon: amoon = v2 / R = 4?2R / P2
- If due to gravitation, then also: amoon = F / mmoon = GMearth / R2
If we know P (period of moon = 1 lunar month), R (distance to the moon) ,
G (unversal constant measured much later) We can determine the mass of the earth!
But Newton Did not know the value of G!