Please stick to one name, don't switch names from one post to another.

this question is similar to the one you posted as Katlyn

since the radius is 7 m, a = 7

remember : period = 2π/k , where k is the coefficient of your trig function ... sin (kt)

so 2π/k = 16

16k = 2π

k = 2π/16 = π/8

so far we have height = 7 sin (π/8)t

the way the curve is, and ground is zero, the lowest point would be -7, but we want the lowest point to be 1.5, so wouldn't we have to raise the curve up 8.5 ?

so far we have : height = 7 sin (πt/8) + 8.5

since you did not state where you want the bottom of the wheel to be at a given time, I cannot find the phase shift

As the wheel slows down, the period would become longer, and the sine curve would be stretched horizontally, nothing happens vertically.