Distance of Image from Object in Plane Mirror - Caution with Convex Mirrors

In summary, the distance between an object and its image in a plane mirror can be calculated using the distance between the object and an observer. However, in convex mirrors, the image is always closer to the mirror than the object. This may cause confusion for observers who are not aware of this fact, leading to the cautionary warning on car mirrors. This is because the angle subtended by the image in a convex mirror is smaller than the angle subtended by the object, making it appear farther away than it actually is.
  • #1
louie3006
54
0
Q#1. Homework Statement [/b]
an object and an observer are located 2meter in front of a plane mirror, If the observer is 3meter from the object, find the distance between the observer and the location of the object's image.

Q#2. the image produced by a convex mirror is always closer to the mirror than the object. Then why is it that the convex mirror used on cars often say "caution: objects are closer than they appear" printed on them?
 
Physics news on Phys.org
  • #2
Q#2 Angle subtended by an object to the eyes of an observer is small if the object is away from him. In the convex mirror angle subtended by the image is smaller than the angle subtended by the object ,if he see the object behind him directly. So, if the observer is ignorant about the nature of the convex mirror and assumes it as plain morror, then to him the object appears to be at a larger distance than the actual distance. Hence the caution.
 
  • #3


I would like to clarify that the distance between the object and its image in a plane mirror is always the same as the distance between the object and the mirror. Therefore, in the given scenario, the distance between the observer and the location of the object's image would also be 2 meters. This is because, in a plane mirror, the image is formed at the same distance behind the mirror as the object is in front of it.

As for the second question, while it is true that the image produced by a convex mirror is closer to the mirror than the object, it is also important to consider the size of the image. Convex mirrors produce smaller images than the actual objects, which can give the illusion that the objects are farther away than they actually are. This is why the warning "objects are closer than they appear" is printed on convex mirrors used in cars, as it serves as a reminder for drivers to be cautious when judging the distance of objects seen in the mirror.
 

1. What is the distance of the image from the object in a plane mirror?

The distance of the image from the object in a plane mirror is equal to the distance of the object from the mirror. This is known as the "law of reflection", where the angle of incidence (incoming light ray) is equal to the angle of reflection (outgoing light ray). This means that the image appears to be the same distance behind the mirror as the object is in front of the mirror.

2. Why is caution necessary when using convex mirrors for distance measurements?

Caution is necessary when using convex mirrors for distance measurements because these mirrors have a curved surface that causes light rays to diverge (spread out) rather than converge (come together). This means that the image formed in a convex mirror is smaller and distorted compared to the actual object, making it difficult to accurately determine the distance of the image from the object.

3. Can the distance of the image from the object in a plane mirror be negative?

No, the distance of the image from the object in a plane mirror cannot be negative. The distance is always measured as a positive value, regardless of the position of the object and image relative to the mirror. This is because the distance is a measure of the physical separation between the object and the image, not their direction.

4. How does the size of the object affect the distance of the image from the object in a plane mirror?

The size of the object does not affect the distance of the image from the object in a plane mirror. As long as the object is in front of the mirror, the distance of the image from the object will always be equal to the distance of the object from the mirror. This is due to the law of reflection, where the angles of incidence and reflection are equal regardless of the size of the object.

5. Can the distance of the image from the object in a plane mirror be greater than the actual distance between the object and the mirror?

No, the distance of the image from the object in a plane mirror cannot be greater than the actual distance between the object and the mirror. This is because the image appears to be behind the mirror at the same distance as the object is in front of the mirror, and the distance between the object and the mirror is always greater than or equal to zero.

Similar threads

  • Introductory Physics Homework Help
Replies
5
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
1K
  • Introductory Physics Homework Help
Replies
14
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
3
Views
3K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
3K
Back
Top