How Do Light Rays and Mirror Equations Affect Image Formation?

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    Light Mirror Rays
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Discussion Overview

The discussion revolves around various problems related to light rays, mirror equations, and image formation, focusing on concepts such as reflection types, image characteristics, and practical applications of mirrors. The scope includes homework-related questions and conceptual clarifications in physics.

Discussion Character

  • Homework-related
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • Some participants inquire about the use of parallel light rays to differentiate between regular and diffuse reflection, suggesting that diffuse reflections scatter light at various angles.
  • There is a question regarding the reversal of letters on signs, with examples like fire engines and rear-view mirrors provided to illustrate this phenomenon.
  • Participants discuss how the type of image formed by a concave mirror changes as an object moves along the principal axis, with references to diagrams illustrating light ray paths.
  • The distinction between real and virtual images is raised, with a suggestion that real images can be projected onto a screen.
  • Some participants explain that concave mirrors can produce both real and virtual images due to the convergence of light rays, while convex mirrors can only produce virtual images.
  • Applications of concave mirrors in searchlights and solar ovens are mentioned, with a request for diagrams to demonstrate the principle of light reversibility.
  • Participants are asked to compare the properties of images formed by plane and convex mirrors, particularly in the context of security applications.
  • Specific numerical problems regarding angles of incidence and reflection are presented, with some participants clarifying the relationship between angles and the normal line to the mirror surface.

Areas of Agreement / Disagreement

Participants express varying levels of understanding and approaches to the homework questions, with some providing hints and others emphasizing the need for textbook reading. There is no clear consensus on the solutions to the problems presented.

Contextual Notes

Some responses rely on visual diagrams that are not provided, and there are assumptions about the reader's familiarity with certain terms and concepts, such as the definition of angles and the normal line.

Who May Find This Useful

This discussion may be useful for students struggling with concepts of light and mirrors in physics, particularly those seeking help with homework problems related to reflection and image formation.

banana44
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hey guys i really need help with these problems.I am not good with physics at all, i just need this to graduate . I really don't understand it and my teacher isn't much help. If anyone can help me out with this i would really appericiate it.
Thank you.

1.Why are parallel light rays used to show the difference between regular and diffuse reflection?
2.List some situations where the letters on signs are reversed. Explain why it is being done.
3.As the object is moved along the principle axis toward the vertex of a concave mirror, the type of image changes. Where does the change in type of image occur? Explain why, in terms of the path of the light rays.
4.Explain the difference between a real and virtual image.
5.Explain why concave mirrors can produce real or virtual image, but convex mirrors can produce only virtual image.
6.Concave mirrors are used in searchlights and solar ovens. Draw two diagrams to show the path of light in each case, and explain why these two applications demonstrate the principle of the reversibility of light.
7.Describe the similarities and differences of the properties of the images formed in a plain mirror and a convex mirror. Why are convex mirrors used for security purposes in stores, rather than plane mirrors?
8.Usha wants to take a picture of her own image in a plane mirror. At what distance should the camera lens be focussed if it is positioned 2.3 m in front of the mirror?
9.A ray of light strikes a mirror at an angle of 550 to the normal.
a)What is the angle of reflection?
b)What is the angle between the incident ray and the reflected ray?
10.A ray of light strikes a mirror at an angle of 570 to the mirror surface. What is the angle between the incident ray and the reflected ray?
11.What is the angle of incidence if the angle between the reflected ray and the mirror surface is 340?
12.Light is shining on to a plane mirror at an angle of incidence of 270. If the plain mirror is tilted such that the angle of incidence is reduce by 80, what will be the total change in the angel of reflection from the original reflected light?
 
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The mutual silence here speaks volumes...you need to read your textbook! :)
 
Severian596 said:
The mutual silence here speaks volumes...you need to read your textbook! :)

yeah but if someone doesn't understanding a subject; doesn't matter how much they read the textbook.
Isnt that why this site was made? to help people understand the work ?
 
banana44 said:
hey guys i really need help with these problems.I am not good with physics at all, i just need this to graduate . I really don't understand it and my teacher isn't much help. If anyone can help me out with this i would really appericiate it.
Thank you.
The homework forums are to help people who are stuck on problems - not just an answers in the back generator. Here are some hints.

1.Why are parallel light rays used to show the difference between regular and diffuse reflection?
In diffuse reflections the light bounces off at all angles.

2.List some situations where the letters on signs are reversed. Explain why it is being done.
Do FIRE engines in your country have ERIF painted on the front? How do you see vehicles behind you in a car?

3.As the object is moved along the principle axis toward the vertex of a concave mirror, the type of image changes. Where does the change in type of image occur? Explain why, in terms of the path of the light rays.
Look up the diagram for a concave mirror showing rays from in front/at/behind the focus.

4.Explain the difference between a real and virtual image.
Screen

5.Explain why concave mirrors can produce real or virtual image, but convex mirrors can produce only virtual image.
To get a real image rays must converge - draw the rays hitting each type of mirror.

6.Concave mirrors are used in searchlights and solar ovens. Draw two diagrams to show the path of light in each case, and explain why these two applications demonstrate the principle of the reversibility of light.
Focus a parallel beam at a point or produce a parralel bema from a point.

7.Describe the similarities and differences of the properties of the images formed in a plain mirror and a convex mirror. Why are convex mirrors used for security purposes in stores, rather than plane mirrors?
What range of angles can you refelct from the mirror

8.Usha wants to take a picture of her own image in a plane mirror. At what distance should the camera lens be focussed if it is positioned 2.3 m in front of the mirror?
The image is the same distance behind the mirror that the object is in front.
9.A ray of light strikes a mirror at an angle of 550 to the normal.
a)What is the angle of reflection?
b)What is the angle between the incident ray and the reflected ray?
10.A ray of light strikes a mirror at an angle of 570 to the mirror surface. What is the angle between the incident ray and the reflected ray?
11.What is the angle of incidence if the angle between the reflected ray and the mirror surface is 340?
12.Light is shining on to a plane mirror at an angle of incidence of 270. If the plain mirror is tilted such that the angle of incidence is reduce by 80, what will be the total change in the angel of reflection from the original reflected light?
I assume the extra 0 on each of these is a deg symbol?
All you need to know is that if you draw a line from the mirror outward at 90deg to the surface (called a normal) the light reflects with the same angle from this line that it had when it arrived - bit on the other side.
 

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