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Answered

Camera lenses are described in terms of
their focal length. A 50 mm lens has a focal
length of 50 mm. A camera is focused on an
object 13 m away using a 120 mm lens.
Locate the position of the image.
Answer in units of mm.

Answer :

Answer:

The position of the image from the camera lens is approximately 121.1 mm

Explanation:

The given parameters of the lens are;

The specification of the camera lens = 120 mm

Therefore, the focal length of the camera lens, f = 120 mm = 0.12 m

The distance of the object from the camera, [tex]d_o[/tex] = 13 m

The lens equation for finding the position of the image is given as follows;

[tex]\dfrac{1}{f} = \dfrac{1}{d_o} + \dfrac{1}{d_i}[/tex]

Where;

[tex]d_i[/tex] = The position of the image from the camera lens

Therefore, by plugging in the known values, we have;

[tex]\dfrac{1}{13} = \dfrac{1}{0.12} + \dfrac{1}{d_i}[/tex]

[tex]\dfrac{1}{d_i} = \dfrac{1}{0.12} - \dfrac{1}{13} = \dfrac{13 - 0.12}{0.12 \times 13} = \dfrac{12.88}{1.56} = \dfrac{322}{39}[/tex]

[tex]\therefore d_i = \dfrac{39}{322} \approx 0.1211[/tex]

The position of the image from the camera lens, [tex]d_i[/tex] = 0.1211 m = 121.1 mm

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