Posted by sophie on Friday, May 29, 2009 at 7:43pm.
The paddle wheel of a boat measures 16 feet in diameter and is revolving at a rate of 20 rpm. The maximum depth of the paddle wheel under water is 1 foot. Suppose a point is located at the lowest point of the wheel at t=0.
1. Write a cosine function with phase shift 0 for height above water of the initial point after t seconds.
a. h=8cos((2π)/2 t)+7
b. h=8cos3t+7
c. h=8cos((2π)/3 t)+7
d. h=8cos3t+7
I think this is C?
2. use your function to find the height of the initial point after 5.5 seconds.
a. 7.5 ft
b. 11 ft
c. 10.4 ft
d. 6.5 ft

Math  bobpursley, Friday, May 29, 2009 at 8:02pm
The period is clearly 60/20 seconds, or 3 seconds.
the cosine function should be of the form
cos(2PI/period* t)
C. is correct. 
Math  sophie, Friday, May 29, 2009 at 8:26pm
so would 2. be C as well?