Figure (a) shows the basic structure of a camera. A lens can be moved forward or back to produce an image on film at the back of the camera. For a certain camera, with the distance i between the lens and the film set at f = 6.98 cm, parallel light rays from a very distant object O converge to a point image on the film, as shown. The object is now brought closer, to a distance of p =210 cm, and the lens-film distance is adjusted so that an inverted real image forms on the film (Figure (b)). (a) What is the lens-film distance i now (in cm)? (b) By how much (in cm) was distance i changed? (&) (a) Number n Units ~ (b) Number n Units v