Physics: Principles and Problems
Chapter 7 Vocab
Kepler's first law - ✔️✔️States that the planets move in elliptical paths, with the Sun always at one
focus.
Kepler's second law - ✔️✔️States that an imaginary line from the Sun to a planet sweeps out equal
areas in equal time intervals.
Kepler's third law - ✔️✔️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.
Gravitational force - ✔️✔️The attractive force between two objects that is directly proportional to
the mass of the objects.
Law of universal gravitation - ✔️✔️States that gravitational force between any two objects is directly
proportional to the product of their masses and inversely proportional to the square of the distance
between their centers.
Gravitational field - ✔️✔️The field that surrounds any object with mass; equals the universal
gravitational constant, times the mass of the object, divided by the square of the distance from the
object's center.
Inertial mass - ✔️✔️A measure of an object's resistance to any type of force.
Gravitational mass - ✔️✔️The size of the gravitational force between two objects.
