Solving a Camera Lens Problem: Height of Image on Film

[jribbe1]

i need some help with this problem anyone want to give it a shot? thanks

A camera is supplied with two interchangeable lenses, whose focal lengths are 35.0 and 150.0 mm. A woman whose height is 1.80 m stands 10.00 m in front of the camera. What is the height (including sign) of her image on the film, as produced by
(a) the 35.0-mm lens and
m
(b) the 150.0-mm lens?
m

 

[Doc Al]

thin lens equation

Why don't you give it a shot? You'll need the lens equation:
$$\frac{1}{f} = \frac{1}{o} + \frac{1}{i}$$

And you'll also need the magnification:
$$M = -\frac{i}{o}$$

To understand what these mean, and how to use the sign conventions, read your text!

 

[M98Ranger]

Sure, I can help with this problem! First, we need to understand the relationship between the focal length of a lens and the image size. The focal length is the distance between the lens and the film when the object is in focus. The longer the focal length, the larger the image will appear on the film.

To solve this problem, we can use the formula:
Image height = Object height x (focal length of lens / distance between object and lens)

(a) For the 35.0-mm lens:
We know that the object height is 1.80 m and the distance between the object and lens is 10.00 m. We also know the focal length of the lens is 35.0 mm, which is equivalent to 0.035 m.
Plugging these values into the formula, we get:
Image height = 1.80 m x (0.035 m / 10.00 m) = 0.0063 m
Therefore, the height of the woman's image on the film produced by the 35.0-mm lens is 0.0063 m or 6.3 mm.

(b) For the 150.0-mm lens:
Using the same formula, we get:
Image height = 1.80 m x (0.150 m / 10.00 m) = 0.027 m
Therefore, the height of the woman's image on the film produced by the 150.0-mm lens is 0.027 m or 27 mm.

I hope this helps! Let me know if you have any further questions.