State the law of universal gravitation. Discuss that the product of the masses of two affects the gravitational attraction. Elicit that the force is directly proportional to the product of the two masses. Use examples to mathematically show how the force between two objects will differ by the square of the distance. Introduce the formula F is directly proportional to the product of the masses and inversely proportional to the distance squared. Rewrite the formula as F= G (M1M2) / D^2