Question

Item 6 6 of 7 > Constants Two converging lenses are placed 39.5 cm apart. The focal length of the lens on the right is 18.0 cm and the focal length of the lens on the left is 11.0 cm . An object is placed to the left of the 11.0 cm focal-length lens. A final image from both lenses is inverted and located halfway between the two lenses. Part A How far to the left of the 11.0 cm focal length lens is the original object? O 2 ? IVO ALOM d. = 7.1 Submit Previous Answers Request Answer X Incorrect; Try Again; 2 attempts remaining Provide Feedback Next >

Answer 1

using lens formula for right lens

1/f = 1/v' - 1/u'

1/18 = - 1/(39.5 /2) + 1/u'

u' = 9.417 cm

now since the above object is resultant image formed by left lens

imgae distance of which is given by

v = 39.5 - 9.417 = 30.08 cm

using lens formula for left lens

1/f = 1/v - 1/u

1/11 = 1/30.08 + 1/u

u = 17.3417 cm

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