Question

Centered 7 meters above the ground, a Ferris wheel of radius 6 meters is rotating with angular speed 24 degrees per second.

a. Assuming that you begin at time t = 0 seconds at the lowest point on the wheel, find a formula that describes the distance h (in meters) from you to the ground after t seconds of riding.
b. At what times are you 10 meters above the ground? Please explain clearly how you got your solution.

Answer 1

24 degrees per second is 360 degrees in 15 seconds (pretty fast for a Ferris wheel!).

a) The distance above the ground can be modeled using a cosine function.
.. h(t) = 7 -6cos(2πt/15)


b) h(t) = 10
.. 10 = 7 -6cos(2πt/15)
.. (10 -7)/-6 = cos(2πt/15)
.. 2πt/15 = π ±π/3 +2kπ
. t = 7.5*((1 ±1/3) +2k) . . . . . . . . seconds; k = any integer

You are 10 meters above the ground at t=5 seconds and every 15 seconds thereafter, as well as at t=10 seconds and every 15 seconds thereafter.