In the process of speed, the acceleration is decomposed vertically, one part is used to provide centripetal force, and the other part is used to increase the speed. The centripetal part is a 1=v? /3, acceleration part a2= root (9-v? /3)。 (where v refers to speed, which is a scalar)

a2=dv/dt

Use dv/dt = root (9-v? /3) This differential equation, v=0 when t=0, gives the v-t relationship, and then integrates the distance and divides it by the angular displacement of the radius.