> Ma Bell want to place a telephone cable around the equator. She adds 50 > feet to the length of the cable beyond what is required. This slack in the > cable allows the cable to be strung up above the ground. How high up from > the surface of the earth will the cable stand? You can assume that the > earth is a perfect sphere. > > In your mind, run a sanity check on your answer to see if it makes sense. > Surprisingly, you will be able to walk under the cble easilty. Since the circumference of a circle is C = 2piR, each increase in R obf 1 foot increases the circumference by 2pi feet. since the cable has been increased by 50 feet the radius of the cable-circle will be increased by 50/2pi or about 8 feet!