Two objects are attracting each other with a certain gravitational force.
(a) If the distance between the objects is halved, the new gravitational force will (1) increase by a factor of 2, (2) increase by a factor of 4, (3) decrease by a factor of 2, (4) decrease by a factor of 4. Why?
(b) If the original force between the two objects is 0.90 N, and the distance is tripled, what is the new gravitational force between the objects?