[填空题]
A cyclist accelerates frogyxp xyy0e6 o59yo3gmn4:f b 5m resdih8c6x+/ fkft at a rate of 1 m/$s^2$ How fast will a point on the rim of the tire at the top be moving after 3.0 s? [Hint: At any moment, the lowest point on the tire is in contact with the ground and is at rest — see Fig. 8–51.] $m/s$