Unit Warm-Up
On the first page of this introduction, you saw an image of the earth. Technically, we know that the earth is not an exact sphere, it has mountains and valleys, but it is pretty close. It is close enough to the shape of a sphere that we can use formulas for a sphere to do calculations with the dimensions of the earth. Before we begin this unit, let’s look up some of these dimensions. Once you have completed this unit, come back to this activity and see how closely you can calculate these measures. Go to Dimensions of Earth for more information.
Think & Click: Unit Warm-Up
Complete the Think & Click activity by looking at each problem below, thinking about it, and then clicking on the question to reveal the solution.
1. Approximately what is the radius of the earth?
There are two values for the radius given:
Equatorial radius = 3,963.34 miles
Polar radius = 3,949,99 miles
2. What is the circumference of the earth at the equator?
You can calculate this using C = 2πr = 2π(3,963.34) ≈ 24,902.40 miles
This is the same as the information on the website.
3. What is the surface area (called "superficial area" on the website) of the earth?
196,950,000 square miles.
By the end of this unit, you will be able to calculate this with the given radius.
4. What is the volume of the earth?
360,000,000,000 cubic miles.
By the end of this unit, you will be able to calculate this with the given radius.
