To measure the length of a hiking trail, a worker uses a device with a 2-foot-diameter wheel that counts the number of revolutions the wheel makes. If the device reads 1,100.5 revolutions at the end of the trail, how many miles long is the trail, to the nearest tenth of a mile?
2006-10-24 08:23:15 · 2 answers · asked by saved_by_grace 2 in Science & Mathematics ➔ Mathematics
Circumference of wheel = 2*pi*r = 2*(3.14)*(1 foot) = 6.28 feet
If it makes 1100.5 revolutions, then the number of feet traveled equals:
6.28 feet * 1100.5 revolutions = 6911.14 feet
One mile = 5280.0 feet, so to the nearest tenth of a mile, the trail is this long:
6911.14 / 5280.0 = 1.3 miles
Hope that helps :)
2006-10-24 08:31:25 · answer #1 · answered by Anonymous · 1⤊ 0⤋
Find the circumference of the wheel (pi x d). Multiply C by the number of revolutions. Divide by 5280
2006-10-24 15:35:09 · answer #2 · answered by davidosterberg1 6 · 0⤊ 0⤋