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In the figure below, a pinecone is at distance p 1 = 2.3 m in front of a lens of

ID: 2300913 • Letter: I

Question

In the figure below, a pinecone is at distance p1 = 2.3 m in front of a lens of focal length f = 0.65 m. A flat mirror is at distance d = 2.4 m behind the lens. Light from the pinecone passes rightward through the lens, reflects from the mirror, passes leftward through the lens, and forms a final image of the pinecone.

(a) What is the distance between the lens and the final image?
(b) What is the overall lateral magnification of the pinecone?
(c) Describe the final image.

You MUST use these numbers

Explanation / Answer

p1 = 2.3 m, f = 0.65 m, d = 2.4 m

The image formed by the converging lens is located at a distance

1 / f = 1/p1 + 1/i

1/0.65 = 1/2.3 + 1/i

i = 0.906 m

The image is formed to the right of the lens i.e. 2.4 m