Suppose that we fit a band tightly around the earth at the equator. We wish to raise the band so that it is uniformly supported 7 ft above the earth at the equator. How much extra length would have to be added to the band (not the supports) to do this.
A) about 37 ft
B) about 44 ft
C) about 49 ft
D) about 35 ft
E) about 88 ft

Question

Suppose that we fit a band tightly around the earth at the equator. We wish to raise the band so that it is uniformly supported 7 ft above the earth at the equator. How much extra length would have to be added to the band (not the supports) to do this. ​  ​
A) about 37 ft 
B) about 44 ft 
C) about 49 ft 
D) about 35 ft 
E) about 88 ft

Quizplus · Accepted Answer

The circumference of the earth at the equator is approximately 24,902 miles. To raise the band 7 ft above the earth at the equator, we need to add the diameter of the band (which is equal to the circumference of the earth) to 2 times the height it is raised. 
So, the extra length of the band would be:
(24902 + 2(7)) - 24902 = 44 ft (rounded to the nearest foot).

Suppose That We Fit a Band Tightly Around the Earth