- The magnification is
(The fact that the magnification is negative confirms that the
image is inverted, as we said in Question 12.) The height of the
image is
hi = |m| • ho = (4 cm) = 6 cm
Questions 15-18
An object of height 4 cm is placed 20 cm in front of a convex mirror
whose focal length is −30 cm.
- Where’s the image?
- Is it real or virtual?
- Is it upright or inverted?
- What’s the height of the image?
Here’s How to Crack It
- With so = 20 cm and f = −30 cm, the mirror equation gives us:
So the image is located 12 cm behind the mirror.