Posted by john on .
An automobile tire has a radius of 0.280 m, and its center moves forward with a linear speed of v = 18.0 m/s.
(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?
i got a which was 64.2857 but cant figure out part b

physics help 
Henry,
C = 6.28*r = 6.28 * 0.28 m = 1.76 m.
C = Circumference.
T = C / V = 1.76 m / 18 m / s = 0.0977s
= time for one rev = period.
Va = C / T = 6.28 * r / T,
Va = (6.28 * 0.175) / 0.0977 = 11.25 m / s.
Alternate Method:
Va = r2 / r1 * 18 = 0.28 / 0.175 * 18 = 11.25 m / s.