The radius of earth is 3950 miles and oceans cover 69.5% of its surface to an average depth of 12100 feet.

Question

The radius of Earth is 3950 miles, and oceans cover 69.5% of its surface to an average depth of 12100 feet. Calculate the volume of Earth’s oceans in cubic miles, meters cubed, and gallons. Express your answers in scientific notation..

Answer 1

Surface area of a sphere = 1/3 πr²

Let's work in miles

r = 3950

1 mile = 5280 ft, so depth of water d = 12100 / 5280 miles

Volume of water in cubic miles = 1/3 πr² d x 0.695 (you can work that out)

1 mile = 1609 m, so 1 cubic mile = 1609³ m³, so to get volume in m³ multiply your cubic miles by this

A US liquid gallon = 0.00379 m³ so to get in gallons divide your m³ result by this