SAT Physics Subject Test

Chapter 3 Newton’s Laws

NEWTON’S LAW OF GRAVITATION

Newton put forth another important theory about the Universe: Any two objects in the Universe exert an attractive force on each other—called the gravitational force—whose strength is proportional to the product of the objects’ masses and inversely proportional to the square of the distance between them. If we let G be the universal gravitational constant, which is equal to 6.67 × 10-11 N • m2/kg2, then the strength of the gravitational force is given by the equation

The forces F1-on-2 and F2-on-1 act along the line that joins the bodies and form an action/reaction pair.