Practice portal › Electric Potential and Capacitance › Electrostatic Potential Energy
Asked in GUJCET 2015 · Energy of a system of charges
Idea: two electrons repel; the potential energy of the pair is U = 1/(4πε₀)(e²)/r, which is positive.
As the separation r decreases, U increases.
The repulsive force opposes the motion, so the moving electron slows down: its kinetic energy decreases.
Energy conservation: K + U stays constant, so the rise in U equals the fall in K.
So the kinetic energy decreases and the potential energy increases.
Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.
Practise this with a timer