If an object is placed 8 cm from a lens with a focal length of 4 cm, the image is 8 cm from the lens
Let the focal length be represented by f
Let the distance between the object and the lens be represented by u
Let the distance between the image and the lens be v
The focal length, f = 4 cm
The distance between the object and the lens, u = 8cm
The distance between the image and the lens, v = ?
The relationship between the focal length (f), distance between the object and the lens (u), and the distance between the image and the lens (v) is given below:

Substitute f = 4, and u = 8 into the equation above:

Therefore, the image is 8 cm from the lens
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