Hello, monster!

I'll get you started . . .

Wheel radius rolls to the right along straight line with speed .

The path of a point on the rim is given by: .

When is the velocity vector of this point horizontal and what is the speed at this point?

We have: .

. . Hence: .

If the velocity is horizontal, then: .

Then: .

. . Hence: .

You'll have to fine-tune this result.

Some values of produce an undefined form for