You have a small but bright computer display that is only 4 cm wide by 3 cm tall. You will place a lens near the display to
project an image of the display about 2.5 m tall onto a large screen that is 6 m from the lens of the projector.
(a) Should you use a converging lens or a diverging lens?
(b) Approximately, what should the focal length of the lens be?
(c) Suppose that you choose a lens that has the focal length that you calculated in part (b). What exactly should be the
distance from the computer display to the lens?
(d) In order that the screen display be right side up, should the computer display be inverted or right side up?
(e) On another occasion the screen is moved close, so that it is only 4 m from the lens. To focus the image, you have to
readjust the distance between the computer display and the lens. What is the new exact distance from the computer
display to the lens?
(f) How tall is the image on the screen, now that the screen is only 4 m from the lens?
Computational Problems