A ferris wheel is a circle with diameter 122 feet which sits on an 8-foot-tall platform making its overall height 130 feet. It completes two revolutions in 2 minutes and 18 seconds. Assuming the riders are at the edge of the circle, how fast are they traveling in miles per hour? (Round your answer to two decimal places.)

Answer: v = 3.79mph

Step-by-step explanation:

Given:

The diameter d = 122ft

Radius r = 61ft

Time for 2 rev t = 2 mins 18sec = 138s

The rider's speed in rev/sec is given as;

s = 2/138 rev/s

the rider's speed in ft/s is:

v = 2πr * s

v = 2π * 61 * 2/138 ft/s

v = 244π/138 ft/s * 3600s/hr * 1/5280ft/mile

v = 3.79mph

They are traveling at 3.79mph