## Moon Math

Newton’s universal law of gravitation describes the force of a gravitational pull between two bodies. The law is written as follows: *F* = *G* × (*M*_{1}*M*_{2})/*D*^{2}. *G* represents a gravitational constant, *M*_{1} represents the mass of body one, *M*_{2} represents the mass of body two and *D* represents the distance from the center of body one to the center of body two. The force is measured in newtons (N).

Given the following information:

Gravitational constant (*G*) = 6.67 × 10^{-11} N·m^{2}/kg^{2}

Earth’s radius = 6371 km

Earth’s mass = 5.97 × 10^{24} kg

Moon’s radius = 1737 km

Moon’s mass = 7.35 × 10^{22} kg

Distance from Earth to Moon (surface to surface) = 384,000 km

What is the force of the gravitational pull, in newtons, between the Earth and the moon? Express your answer in scientific notation.

The moon moves in a circular orbit around the earth as shown. Given the previous distances and that the speed the moon travels in orbit is 3683 km/h, how many days does it take the moon to complete one rotation around the earth? Express your answer as a decimal to the nearest tenth.

How many times must a piece of paper that is 0.01cm thick be folded onto itself in order for it to reach from the surface of Earth to the moon?