Download Gravity and tidal forces

Gravity and tidal forces
How does the force of gravity between two objects change if
(a) the distance between them doubles?
(b) the mass of one of them doubles?
How would you calculate your weight on different planets?
Explain the ocean tides on Earth.
What causes the moon to always show the same face to the Earth?
Saturn’s striking rings are the product of gravitational tidal forces. Explain
how this occurs.
What is the Roche limit ?
Saturn’s ring system has several shepherding satellites. Describe how these
stabilize the rings using gravity and orbital dynamics.
Within Saturn’s rings and the Asteroid belts, there are gaps with few
objects in them. How does the gravity of the closest planets or moons
produce and stabilize these?
There are several instances of planets whose orbit and rotational periods
are locked into a constant ratio of small integers (like 2 / 3 for Mercury).
How might gravity promote this?
Explain how the tidal forces of Jupiter and its moons produce heat in Io,
driving its volcanoes.