**New York is roughly 3000 miles from Seattle. When it is 10:00 A.M. in Seattle, it is 1:00 P.M. in New York. Using this information, estimate (a) the rotational speed of the surface of Earth, (b) the circumference of Earth, and © the radius of Earth.**

**Answer:**

The distance d travelled by an object is equal to the product of the speed v of the object and

the time taken t by it.

**(a)**

Calculate the rotational speed of the surface of Earth as follows:

Solve for v by substituting **3000 miles** for d and 3 **hours** for t.

Therefore, the rotational speed of the surface of Earth is

**(b)**

Therefore, the circumference of the Earth is **24000 miles .**

**( c)**

Calculate the radius of the Earth as follows:

Therefore, the radius of the Earth is **3820 miles .**