A car is filmed with a camera with a focal length of 20 cm. From what distance is a car photographed

A car is filmed with a camera with a focal length of 20 cm. From what distance is a car photographed if the film is located at a distance of 22 cm from the lens?

To determine from what distance d a car is photographed if the film is located at a distance f from a lens with a focal length F, we use the thin lens formula: 1 / F = 1 / d + 1 / f. We get:

d = F * f / (f – F).

From the condition of the problem it is known that the car is filmed with a camera, the focal length of which is F = 20 cm = 0.2 m, and the film in it is located at a distance of f = 22 cm = 0.22 m from the lens. Substitute the values of the quantities into the calculation formula:

d = 0.2 m * 0.22 m / (0.22 m – 0.2 m); d = 2.2 m.

Answer: the car is photographed from a distance of 2.2 m.