Description: This demonstration illustrates the images formed by convex and concave mirrors.
Equipment:
- Large convex mirror
- Large concave mirror
Setup Procedure:
- Clean the mirrors prior to use
Demonstration Procedure:
- Hold up the concave mirror and point it at the class.
- Note that they are upside down, and very small.
- Now, with your back facing the class, hold the mirror up near your face and slightly to one side.
- The students can now see a very large image of your face which is upright. Turn from side to side so the whole class can see you.
- This happens because a concave mirror will simply create an inverted real image when the object is beyond the focal point. When the object is within the focal point, the mirror produces a very lage virtual image that is upright. At the focal point there is no image.
- Hold up the convex mirror and point it at the class.
- Note that they are right side up, and each person can see a wider view of the class than with the concave mirror.
- Now, with your back facing the class, hold the mirror up near your face and slightly to one side.
- The students see a slightly smaller image of your face which is right side up.
- This is because a convex mirror always produces a virtual image no matter where the object is located.
- Explain, that due to their large field of view, these mirrors are used in stores for security purposes and on driveways and streets where traffic is not visible.
28-L4
