The height above ground of a rider on a Ferris Wheel is modelled by the function h (t) = 13 sin (14 (t - 4)) + 15, where t represents time in seconds and h (t) represents the height in meters of the rider above the ground.
a) What is the initial height of the rider above the ground?
b) How long does the Ferris wheel take to complete one rotation?
c) What is the highest point above the ground that the rider reaches on the Ferris wheel?