[填空题]
Starting from rest in thc zq :)hln/7i ym-ez .kpl46nln( 64wz.drheie pit area, a race w d4m4,vthgnvi 2)6tb5if.dg car accelerates at a uniform rate to a speed of 45 m/s in 15 s, moving on a circular tr4)g,i6n ti 2vdw b.hm5df t4gvack of radius 500 m. (only fill in 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. $m/s^2$
