posted by Freda .
A proton is released 2*10^-11 from the center of an immovable 6.4*10^-18 C charged sphere. What is the speed of this proton when it is 0.50mm from the center of the sphere?
Kinetic energy = (1/2) m v^2
Change of potential energy = kinetic energy.
Do the other problem the same way.