Consider an object with do=12cm?o=12cm that produces an image with di=15cm?i=15cm. Note that whenever you are working with a physical object, the object distance will be positive (in multiple optics setups, you will encounter "objects" that are actually images, but that is not a possibility in this problem). A positive image distance means that the image is formed on the side of the lens from which the light emerges.

Part A Find the focal length of the lens that produces the image described in the problem introduction using the thin lens equation. Express your answer in centimeters, as a fraction or to three significant figures. f = 6.67 cm Submit Previous Answers Correct Important: If you use this answer in later parts, use the full unrounded value in your calculations.