### Home > PC3 > Chapter 11 > Lesson 11.2.4 > Problem11-135

11-135.

A paddle wheel has a diameter of $10$ ft. When $t = 0$, Jenn notices a weed stuck to the top of the paddle, which is $8$ ft above the surface of the water. It takes $12$ seconds for the paddle to return to the same position. Write the equation of a function that will model the height of the weed above the water at any time $t$.

A paddle wheel has a diameter of $10$ ft, so the amplitude is ___.

Since the top of the wheel is at $8$ ft above the water, the bottom of the wheel is at $2$ ft below the water. Hence the vertical shift is ___.

The period is $12$ seconds, so $b$ = ___.

When $t = 0$, the weed is at the top of the wheel, so use a (sine or cosine?) function.