PE of system is given by $$\mathrm{U(r) = \frac{-Ke²}{r^3}}$$ assume bohr model to be valid Find velocity
For this I used $\mathrm{\frac{-PE}{2} =KE}$ and then used $$\frac{mv^2}{2} =\frac{Ke^2}{2r^3}$$ and $$mvr=\frac{nh}{2\pi}$$
However, I am getting the answer as $$v=\frac{n^3h^3}{16Ke^2\pi^3m^2}$$ but the answer given has a factor of 24 rather than 16. I don't know where I'm going wrong.