The formula to relate linear and angular velocity is

where omega is the angular velocity and r is the raduis of the circle so solving for omega we get

Since we want the wave to start at its lowest point we will use the cosine function but cos(0)=1 so we will reflect it accross the x-axis and use -cos(0)=-1 or -cos(x) Since the radius of the tire is 30cm we need the amplitude of the wave to be 30cm and we need to shift it up 30cm as well so we get

We can use the angular velocity found in the beginning for something to get

I hope this helps.

Good luck.