Understand that gravitational force is the weakest of the four fundamental forces.

Use Newton’s Universal Law of Gravitation to compare the magnitude of gravitational attraction between two objects depending directly on the product of their masses and inversely on the square of the distance between them.

Compare Newton’s analysis of gravitational force to Kepler’s Laws to show that planetary orbits must be elliptical.

Understand how general relativity theory depicts Newton’s gravitational force as a distortion of space and time.

Students often believe that earth’s gravity does not extend beyond earth’s atmosphere or that it is caused by the atmosphere. Also, they often think there is no gravity on the moon.

Gravitational forces are often thought of as large compared to “trivial” electric forces.

Show how the principle of universal gravitation explains the architecture of the universe through examples such as star formation, tides and the orbits of comets and, through the study of historical aspects, show how this unites the earth and the sky.

Most students at the 11th and 12th grade level should also be able to handle the mathematics necessary to make quantitative sense out of the law of gravitation.