Physics short answer

When an object moves in a circle the arc length s=r is then angular displacement.

Every particle in the universe attracts every other particle with a force that is directly proportional to the product of the masses and inversely proportional to the square of the distance between them

F=G(m1m2/r^2)

When an object moves around another object

Ex. It takes the Earth 365 days for a full revolution around the sun.

The speed an object needs to leave earth

A line drawn from the sun to any planet will sweep out equal areas in equal times

The average angular speed, w, of a rotating rigid object is the ratio of the angular displacement to the time interval