Another form of a curved mirror is a convex mirror . The front of the convex mirror ( shiny part ) is the part that curved out (protrude). This mirror can be obtained from the slices with the ball gives amalgam coating on the concave side (inner), so that the outer side acts as a reflector.
Convex mirror will be discussed only convex mirror which is a spherical shell slices . Thus , the center is also a ball that sliced ??the center of curvature mirror .
 |
| Figure II.9 Illustration convex mirror |
Based II.9 image above , it can be defined some of the terms contained in a convex mirror as follows :
- Point F is called the focal point or fire point mirror .
- M point is called the center of curvature mirror .
- The point O is called the center of the mirror field .
- Line through the point O and M is called the major axis .
- Distance OM = R is called the radius of curvature of the mirror .
Convex mirror reflection on the law as the law of reflection in the mirror the other . On convex mirror, the direction all the normal line at any point in the field of reflection away from the center of curvature. By using the law of refraction of light, we can see the reflection of any light beam toward the surface of the convex mirror.
Reflected beam always come away from the main axis . In other words , the reflected rays of light which comes always deployed . Because it is always spreading sunshine , then called a convex mirror diverging mirror .
The focal point of a convex mirror located behind the mirror so that the focal point is called the focal point of the virtual . Like a concave mirror , the convex mirrors are also three special rays , namely :
a. Beam is parallel to the major axis comes reflected as if coming from the focal point of the mirror .
 |
| Figure II.10 Reflection rays are parallel to the major axis come on convex mirror |
b . Beam coming toward the virtual focal point will be reflected parallel to the main axis .
 |
| Figure II.11 reflection rays coming toward virtual focal point on convex mirror |
c . The main beam toward the center of curvature mirror reflected back as if coming from the center of the curvature .
 |
| Figure II.12 reflection rays coming toward the center of curvature on convex mirror |
Various experiments were conducted to determine the relationship between the object distance , the distance a shadow , and the focal point showed that the equation applicable to the concave mirror is also true for a convex mirror . However , there are some records relating to the use of the equation , namely :
- a. Because the center of curvature of mirrors and mirror located at the focal point behind the mirror , then the calculation of the radius of the mirror ( R ) and focal length ( f ) is always a negative sign .
- b . Because the image produced is always illusory , then the shadow distance calculations ( Si ) always is negative.
Thus , the equations used in the calculation of the convex mirror is the same as that used on the concave mirror , namely :
1 1 1
+ = ................................. ( 2.10)
So Si f
1 1 2
+ = ................................. ( 2.11)
So Si R
- The hi
M == .............................. ( 2.12)
so ho
Description :
So = the distance from the object to the center of the mirror field .
Si = the distance from the shadow to the center of the mirror field .
ho = height of objects .
hi = high shadows .
M = magnification of objects .
Convex mirror always minimize shadows of objects . Therefore , the range view mirror is wider than a flat mirror and a concave mirror that same extent . In other words , the main benefit is a convex mirror to expand the area of view .
Convex mirrors are widely used as a vehicle rearview mirror. Convex mirrors can also be used to observe the vehicle from the opposite direction on the street who has a sharp bend. This mirror is placed in the corner of the road so the driver of the vehicle in the opposite direction can see each other so that collisions can be avoided. Furthermore, a convex mirror is also used to prevent theft in the big stores or supermarkets . This mirror is placed at a certain position that allows visitors movement can be monitored through this mirror . This mirror is usually placed in the corner of the room .
 |
| Figure II.13 Examples formation convex mirror images |
No comments:
Post a Comment