Question

An energy of 0.2 J is stored in the metal ball
on top of a Van de Graaff machine. A spark
carrying 2 µC discharges the ball.
What was the ball’s potential relative to
ground?
Answer in units of V.

Answer 1

The potential energy U of the sphere is given by 1/2 Q V. use that -- > V = 2 • 0.2 / 2•10^-6 V