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### Course: AP®︎/College Physics 2>Unit 5

Lesson 2: Mirror formula and magnification

# Magnification formula for mirrors

Let's explore how to calculate image height and it's nature (real or virtual) using magnification formula. Created by Mahesh Shenoy.

## Want to join the conversation?

• But why magnification only deals with height and not other measures like width ?
• IMO, in the context of magnification, height and width are proportional, so if magnification is 2, then both the height and width are multiplied by 2.

I think they only take height in numericals to avoid confusing students
• a concave mirror produces a 3 times magnified real image of a object placed at 10 cm in front of it. where will the image be located?
• m= -3 (as the image is real)
u = -10cm
v=?

m=-v/u
-v=mu
-v=-3×-10
-v=30
Therefore, v = -30cm
$m$, is measured to be
$m=-1.8$.