A diverging lens (n 5 1.50) is shaped like that in Active Figure 23.25c. The radius of the first surface is 15.0 cm, and that of the second surface is 10.0 cm. (a) Find the focal length of the lens. Determine the positions of the images for object distances of (b) infinity, (c) 3u f u, (d) u f u, and (e) u f u/2.
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
