Question

An object is 16.0cm to the left of a lens. The lens forms an image 36.0cm to the right of the lens. a) What is the focal length of lens? (5 pts) b) Sketch the ray diagram considering an extended object? (Spts) c) Calculate the magnification? Describe the image type?

Answer 1

Answer:

-2.25

Real and inverted image

Explanation:

u = Object distance =  16 cm

v = Image distance = 36 cm

f = Focal length

Lens Equation

$\frac{1}{f}=\frac{1}{u}+\frac{1}{v}\\\Rightarrow \frac{1}{f}=\frac{1}{16}+\frac{1}{36}\\\Rightarrow \frac{1}{f}=\frac{13}{144}\\\Rightarrow f=\frac{144}{13}=11.07\ cm$

Focal length of the lens is 11.07 cm. Positive value indicates the lens is a convex lens

Magnification

$m=-\frac{v}{u}\\\Rightarrow m=-\frac{36}{16}\\\Rightarrow m=-2.25$

Since magnification is negative the image inverted