[填空题]
A cyclist accelerates from restiup7p+ :f1/ 2zlbteo l2n p zo.d2xor4rs-ns6at 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.] $m/s$