A measure of an object's resistance to any type of force. 

It occurs when the Moon passes behind the Earth in relation to the Sun. 

A vector quantity that relates the mass of an object to the gravitational force it experiences at a given location; represented by the symbol g.

The closest point in the Moon's orbit to the Earth.

the state in which the orbital and rotational periods of a body in orbit are equal. 

Establishes that an imaginary line from the Sun to a planet sweeps out equal areas in equal intervals of time. 

Indicate that the planets move in elliptical paths with the Sun at one of the foci.

It states that the square of the ratio of the periods of any two planets is equal to the cube of the ratio of their average distances from the Sun.  

Establishes that the gravitational force between two objects is directly proportional to the square of the distance between their centers.