I need help doing this algebra problem. Look at the details. Please! :)

Question

Mark Twain sat on the deck of a river steamboat. As the paddle wheel turned, a point on the paddle blade moved so that its distance, d, from the water was a sinusoidal function of time.The wheels radius was 10ft and it completed a revolution every 16 seconds.

Four seconds after he stops his stopwatch the point was at its minimum, two feet below the water's surface.

What is the amplitude? (A)
Where is the midline? (C)
What is the period?
What is the frequency (B)?
What is the phase shift? (D)
and then sketch a graph that models the distance from the waters surface as a function of time. Make sure your graph identifies all key feautures inluding specific points, properly labeled and scaled axes, and has at least two full cycles.

Answer 1

The amplitude is the wheel's radius, 10 feet.

 

Since it goes 2 feet under water, the midline is -2 + 10 = 8.

 

The period is the time of one revolution, 16 seconds.

 

16 = 2pi/|B|

16|B| = 2pi

|B| = pi/8

 

B = pi/8

 

One ration takes 16 seconds, this means it should be at its minimum at 8. Because it's at 4 seconds, the graph is moved 4 to the left, so C = 4 (because positive moves left and negative moves right).