80 km/h = 22.2 m/s
66 cm = 0.66 m
Relative to the woman riding in the car:
(a) Since the center of the tire is not moving, and the woman goes along with the movement of the car, v=0
(b) v = +22.2 km/h, since the wheel turns at this velocity from left to right
(c) v = -22.2 km/h, since the wheel turns at this velocity from right to left
(d) a = 0, since v=0
(e) a = v2/r = (+22.2)^2/(0.66 ÷2) = 1493.45 m2/s
(f) a = v2/r = (-22.2)^2/(0.66 ÷2) = -1493.45 m2/s
Relative to hitchhiker:
(g) v = +22.2 m/s, since from an external body, the velocity of the car is still observed
(h) v = +22.2 x 2 = 44.4 m/s, since the top runs twice faster to be able to move the car
(i) v = 0, since from an external body, the bottom part of the tire is always in contact with the ground
(j) a = 0, because velocity is constant
(k) a = 1493.45 m2/s, same with that of the woman because both are inertial reference
(l) a = -1493.45 m2/s, same with that of the woman because both are inertial reference
