[填空题]
A cyclist accelerates from refz8qzp;xr n/3 r x95pist at a rateq*3;m /3s boj/h*1egyksb n pm 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.] $m/s$