[填空题]
Starting from rest in the eeznrak, fh+4jg; uo 871i-xps ;l*atpit area, a race c*anz 38) tvp ty8izmn5nz:x l+ar accelerates 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 i* 8vxn8+ nzi35plt:z matny z)n numerical value 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. $m/s^2$
