What is the radius of a hydrogen atom whose electron moves a

What is the radius of a hydrogen atom whose electron moves at 2.4 × 105m/s?

mV^2/r = Ze^2/(4pi*apsalan*r^2)

centrifugal force = electrostatic force

=> R = 1*(1.6*10^-19)^2/(9.1*10^-31*(2.4*10^5)^2*0.5*8*3.14*8.85*10^-12) = 4.39 nm