Question

A bicyclist races on a bicyclist with 13-inch-radius wheels. When she is traveling at a speed of 37 ft/sec, how many revolutions per minute are her wheels making?

Answer 1

Radius of a wheel = 13 inch
= 1.08333 ft
circumference of a wheel = 2×pi×r^2
= 2 × (22/7) × 1.08333^2 ft
= 2 × (22/7) × 1.1736 ft
= (44/7)×1.1736 ft
= 51.6384/7 ft
= 7.3769142857 ft
distance covered in one minute = 37 × 60 ft/min
= 2220 ft/min
now, revolution per minute = 2220 / 7.3769142857
= 300.93884
therefore her wheels are making 300.93884 revolutions per minute