<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
You are viewing an older version of this Concept. Go to the latest version.

# Concave Mirrors

## Concave mirrors focus light and create reflected images are of different sizes than the original object.

Estimated3 minsto complete
%
Progress
Practice Concave Mirrors

MEMORY METER
This indicates how strong in your memory this concept is
Progress
Estimated3 minsto complete
%
Distorted Images

### Distorted Images

Credit: Eden, Janine and Jim
Source: http://www.flickr.com/photos/edenpictures/2209366634/

Fun house mirrors distort images by either stretching or shrinking the image of the object placed in front of them. As the picture shows, the object in front of the mirror is being elongated by the mirror. Can you guess whether it is a concave or a convex mirror?

#### News You Can Use

• The distortion that is seen when standing in front of fun house mirrors is determined by the angle of the mirror. If the mirror is bulged outward, it is known as a convex mirror. Convex mirrors result in making the object look shorter and wider than it really is. If the mirror is bent inward, it is a concave mirror. This type of mirror makes the object look taller and wider than it really is.
• Spherical mirrors, such as concave and convex mirrors, form the image at a spot called the focal point. The distance from the focal point is called the focal length and is defined as

1s+1s=1f\begin{align*}\frac{1}{s}+\frac{1}{s^\prime}=\frac{1}{f}\end{align*}

where s\begin{align*}s\end{align*} and s\begin{align*}s^\prime\end{align*} are the respective object and image distances. An easy way to determine whether a mirror is concave or convex or if real or virtual images are produced is by looking at the sign of the variables in the above equation.

• Using the following table, you will be able to tell what type of image you will see before looking into a mirror.
 S + if the object is in front of the mirror (real) - if the object is behind the mirror (virtual) S' + if the object is in front of the mirror (real) - if the object is behind the mirror (virtual) F + the curvature is in front of the mirror (concave) - the curvature is behind the mirror (convex)

#### Show What You Know

1. What is the minimum number of rays needed to locate an image that is formed by a mirror?
2. If the focal length approaches infinity for a plane mirror, what relationship exists between the object location and the image location?
3. If the focal length of a convex mirror is -5 cm, and an object is placed 10 cm from the mirror, where is the image formed?

### Notes/Highlights Having trouble? Report an issue.

Color Highlighted Text Notes