As the conducting bar in Figure CQ20.5 moves to the right, an electric fi eld directed downward is set up. If the bar were moving to the left, explain why the electric fi eld would be upward.
Goals • To calculate the electric potential energy of a group of charges • To know the significance of electric potential • To calculate the electric potential due to a collection of charges • To use equipotential surfaces to understand electric potential • To calculate the electric field using the electric potential Electric potential energy in a uniform field • The behavior of a point charge in a uniform electric field is analogous to the motion of a baseball in a uniform gravitational field. A charge moving in a uniform field • If the positive charge moves in the direction of the field, the potential energy decreases, but if the charge moves opposite the field, the potential energy increases. • If the negative charge m
