Question

7. PHOTOGRAPHY Francine has a camera in which the distance from the lens to the film

is 24 millimeters.
a. If Francine takes a full-length photograph of her friend from a distance of 3 meters
and the height of her friend is 140 centimeters, what will be the height of the image
on the film? (Hint: Convert to the same unit of measure.)
b. Suppose the height of the image on the film of her friend is 15 millimeters. If
Francine took a full-length shot, what was the distance between the camera and her
friend?

Answer 1

a) The height of the image = 11.2 millimeters

b) The distance between the camera and her friend = 2.24 meters

Explanation:

Part A: find the height of the image:

distance from the lens to the film = 24 millimeters

distance from the lens to the her friend = 3 meters = 3000 millimeters

height of her friend = 140 centimeters = 1400 mm

the height of the image = x

Using the similarity :

`(x)/(140) = (24)/(3000) \\x= (140*24)/(3000) = 1.12 cm = 11.2 mm.`

Part B: find the distance between the camera and her friend

If the height of the image on the film of her friend is 15 millimeters.

Let the the distance between the camera and her friend = y

`(y)/(24) = (1400)/(15) \\y = (24 * 1400)/(15) = 2,240 mm = 2.24 meters`