[填空题]
Starting from rest in t(ro4 r:e)ayskhe pit area, a race car accell;3vf2.;cpl)l)j-yfa (*apm rr ao hperates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular track of radius 500 m. (only fill in numerical vall;3oryp *.lfa)-a(ppa c2v)mf ljh;r ue in the blanks)
(a) Calculate the tangential acceleration. $m/s^2$
(b) Calculate the radial acceleration when the instantaneous speed is equal to 30 m/s. $m/s^2$
