.
From the closest points on each body.
From the most distant points on each body.
From the center of each body.
From the center of one body to the closest point on the other body.
Inertia
Gravitational force
Planetary force
Kepler’s force
Is greater than the force the moon exerts on Earth.
Is less than the force the moon exerts on Earth.
Is equal in magnitude to the force the moon exerts on Earth.
Causes tides.
The force decreases by a factor of 4.
The force decreases by a factor of 2.
The force increases by a factor of 2.
The force increases by a factor of 4.
Two objects always exert gravitational forces on each other.
The force of gravity depends on the mass and the distance between the two objects.
All objects fall at different rates on earth.
Both a and b.