A paint spot X lies on the outer rim of the wheel of a paddle-steamer. The wheel has radius 3 m and
rotates anticlockwise at a constant rate. X is seen
entering the water every 4 seconds.
H is the distance of X above the bottom of the
boat. At time t=0, X is at its highest point.
A) Find a cosine model for H in the form
H(t) = a cos(b(t – c)) + d.
B) At what time t does X first enter the water?
a