An automobile tire has a radius of 0.380 m, and its center moves forward with a linear speed of v = 19.0 m/s.

Question

(a) Determine the angular speed of the wheel. (Assume that there is no slipping of the surfaces in contact during the rolling motion.)
rad/s

(b) Relative to the axle, what is the tangential speed of a point located 0.175 m from the axle?
m/s I know this is 8.75 m/s

again I am able to answer the second part of the question,but no the first part. I get stuck on the first part.