Question

A camera lens used for taking close-up photographs has a focal length of 22.0 mm. The farthest it can be placed from the film is 32.9 mm. What is the closest object that can be photographed

Answer 1

Answer:

p = 6.64 cm

Explanation:

For this exercise we use the equation of the constructor

          $\frac{1}{f} = \frac{1}{p} + \frac{1}{q}$

where f is the focal length, p and q are the distance to the object and the image, respectively

They tell us the focal length f = 2.2 cm and that the image as far as it can go is q = 3.29 cm, let's find the position of the object that creates this image

          $\frac{1}{p} = \frac{1}{f} - \frac{1}{q}$

          1 / p = 1 / 2.2 - 1/3.29

           1 / p = 0.15059

           p = 6.64 cm

therefore the farthest distance from the object is 6.64 c