1. The problem statement, all variables and given/known data In classical electromagnetism, an accelerated charge emits electromagnetic radiation. In non-relativistic limit, where the velocity of the electron is smaller than c, the total power radiated is given by the Larmor formula, to wit P=2/3*e2*a2/c3, where a denotes the acceleration of the electron. I am expected to use energy conservation, dE/dt=P, to show that in the adiabatic approximation in which the orbit remains nearly circular at all times, the radius of the electron evolves with time as: r3(t)=r3(0)-4r02ct, where r(0) is the initial radius at t=0 and r0=e2/(mc2) is the classical radius of the electron. 2. Relevant equations 3. The attempt at a solution The general expression for energy in circular motion is: E=1/2*m*ω2r2-e/r2 When I differentiate that wrt time and equate the result to P, I obtain the following: md2r/dr2*dr/dt+2e(dr/dt)/r3=2/3*e*(d2r/dr2)2/c3 but I am not sure how to proceed. Any advice?