Because a concave lens cannot form a real image of a real object,it is difficult to measure its focal length precisely. One methoduses a second, convex, lens to produce a virtual object for theconcave lens. Under the proper conditions, the concave lens willform a real image of the virtual object! A student conducting alaboratory project on concave lenses makes the followingobservations: When a lamp is placed 42.5 cm to the left of aparticular convex lens, a real (inverted) image is formed 37.9 cmto the right of the lens. The lamp and convex lens are kept inplace while a concave lens is mounted 13.1 cm to the right of theconvex lens. A real image of the lamp is now formed 35.5 cm to theright of the concave lens. What is the focal length of the convexlens?
What is the focal length of the concave lens?
Because a concave lens cannot form a real image of a real object,it is difficult to measure its focal length precisely. One methoduses a second, convex, lens to produce a virtual object for theconcave lens. Under the proper conditions, the concave lens willform a real image of the virtual object! A student conducting alaboratory project on concave lenses makes the followingobservations: When a lamp is placed 42.5 cm to the left of aparticular convex lens, a real (inverted) image is formed 37.9 cmto the right of the lens. The lamp and convex lens are kept inplace while a concave lens is mounted 13.1 cm to the right of theconvex lens. A real image of the lamp is now formed 35.5 cm to theright of the concave lens. What is the focal length of the convexlens?
What is the focal length of the concave lens?
