WEEK FIVE GRAVITY &
Units of Force: (N = kg x m/s )
*Earth is not moving at a constant velocity
Laws of gravity:
1. Every mass attracts every other mass.
2. Attraction is directly proportional to the product of their masses.
3. Attraction is inversely proportional to the square of the distance between their
F g G (M M1 x 2 2
Q: If two people were twice as close, the force would be?
A: 4 times
Keppler 1 = Elliptical Orbits
Keppler 2 = Eq2 l 3rea = Equal Time
Keppler 3 = p = a (p= yr , a= au)
Kepler’s first 2 laws apply to all orbiting objects – NOT JUST PLANETS
(comets, moons, satellites)