1. In Figure 2, we see that the Moon falls around Earth rather than straight into it. If the Moon’s tangential velocity were suddenly reduced to zero, how would it move?
2. According to the equation for gravitational force, what happens to the force between two bodies if the mass of one of the bodies is doubled? If both masses are doubled?
3. Gravitational force acts on all bodies in proportion to their masses. Why, then, doesn’t a heavy body fall faster than a light body?
1. If the Moon’s tangential velocity became zero, it would fall straight down and crash into Earth!
2. When one mass is doubled, the force between it and the other one doubles. If both masses double, the force is four times as much.
3. Recall the figure, in which heavy and light bricks fall with the same acceleration because both have the same ratio of weight to mass. Newton’s second law (a = f/m ) reminds us that a greater force acting on a greater mass does not result in a greater acceleration.