Solutions
KM#9: Mass and Density of the Earth (Level 3)
Mathematical Content: Geometry (radius and circumference of a circle; volume of a sphere); interior angles; Newton's Law of gravitational attraction; formulas for density and force; solving equations involving kinetic energy, mass and volume
Question 1 What is the mass of the Earth?
Substitute the values given above in the equation 
Solve the equation for ME, the mass of the Earth.
Mg, which is 
.
Question 2 What is the volume of the Earth?
Question 3 What is the density of the Earth?
