[填空题]
Starting from rest in the pit area, a race car accele k)gaspd ,*dh.u kzxn qa3s982-xw1yfrates 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 numer18zfa9s- uxynx2q w k3ical 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. $m/s^2$
