Hello Aspirant !

As given by you in question , A = kt^x (K : Proportionality Quotient and x stands for alpha) ,

Normal Acceleration = v^2/R

Putting Acceleration value in it , v^2 = (kt^x)*R  (R : Radius)

Kinetic Energy(E) = 1/2 mv^2 = 1/2*mkt^xR

Power P = dE/dt = d(1/2*mkt^xR) / dt

Hence ,  P = mkt2R

Hope it helps !