[填空题]
Starting from rest i+,7zbgqc ,acr n the pit()i s9hb(xjdac 6c; kl area, a race car 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 in numerical value in thski ; (ccl)jdh69xa( be blanks)
(a) Calculate the tangential acceleration. $m/s^2$
(b) Calculate the radial acceleration when the instantaneous speed is equal to 30 m/s. $m/s^2$
