# Electrostatics, finding velocity

by physics604
Tags: electrostatics
 P: 92 1. An electron orbits the nucleus of an atom with velocity v. If this electron were to orbit the same nucleus with twice the previous orbital radius, its orbital velocity would now be a) $\frac{v}{2}$ b) v c) 2v d) $\frac{v}{√2}$ 2. Relevant equations $\Delta$Ek + $\Delta$Ep = 0 ? 3. The attempt at a solution I'm not really sure how I should start this question. None of the equations I have include both the v and the r variable.