Because a concave lens cannot form a real image of a real object, it is difficult to measure its focal length precisely. One method uses a second, convex, lens to produce a virtual object for the concave lens. Under the proper conditions, the concave lens will form a real image of the virtual object! A student conducting a laboratory project on concave lenses makes the following observations: When a lamp is placed 44.8 cm to the left of a particular convex lens, a real (inverted) image is formed 36.3 cm to the right of the lens. The lamp and convex lens are kept in place while a concave lens is mounted 14.1 cm to the right of the convex lens. A real image of the lamp is now formed 33.4 cm to the right of the concave lens.
a) What is the focal length of the convex lens?
b) What is the focal length of the concave lens?