Question

Hyun Woo is riding a ferris wheel. H(t) models his height (in m) above the ground, t seconds after the

ride starts. Here, t is entered in radians.

H(t) = -10 cos(2Pi/150 t)+10

When does Hyun Woo first reach a height of 16 m?

Answer 1

`t \approx 52.8\,s`

Explanation:

The following expression needs to be solved:

`10\,m\cdot \left[1-\cos \left((2\pi\cdot t)/(150) \right)\right] = 16\,m`

`1 - \cos \left((2\pi\cdot t)/(150) \right) = 1.6`

`\cos \left((2\pi\cdot t)/(150) \right) = -0.6`

`(2\pi\cdot t)/(150) = \cos^(-1)(-0.6)`

`(2\pi\cdot t)/(150) = 0.704\pi`

`t \approx 52.8\,s`