Moon Math

August 24, 2015

Newton’s universal law of gravitation describes the force of a gravitational pull between two bodies.  The law is written as follows: F = G × (M1M2)/D2G represents a gravitational constant, M1 represents the mass of body one, M2 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·m2/kg2
Earth’s radius = 6371 km
Earth’s mass = 5.97 × 1024 kg
Moon’s radius = 1737 km
Moon’s mass = 7.35 × 1022 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?