Step 1
Given;
[tex]d=30sin(\frac{\pi}{40}t)+20[/tex]Required; How long will it take for the Ferris wheel to make one revolution
Step 2
Let the time for making one revolution be;
[tex]T=\frac{2\pi}{\frac{\pi}{40}}=2\pi\times\frac{40}{\pi}=80seconds[/tex]Note;
[tex]\begin{gathered} For\text{ a trigonometric function} \\ f(x)=asin(wt)+b \\ T=\frac{2\pi}{w} \end{gathered}[/tex][tex]\begin{gathered} T\text{ is the period for one revolution} \\ w=\frac{\pi}{40} \end{gathered}[/tex]Answer;
[tex]80\text{ seconds}[/tex]