Plane Mirror Optics: Determining Minimum Mirror Size for Viewing Entire Image

In summary, the conversation discusses a problem involving a person looking at their reflection in a plane mirror and noticing a dark spot. The person's height and eye position are given, and two questions are asked: the distance between the spot and the floor and the minimum amount of mirror needed to see their entire image. While the first question is solved using a scaled diagram, the person is having difficulty understanding the second question. They ask for help and suggest that the person's position relative to the mirror may affect the amount of mirror needed. A hint is given to draw a diagram and consider the distance between the person and their image.
  • #1
Speedking96
104
0

Homework Statement



While you were looking at the reflection of your feet in a plane mirror,
you saw a dark spot on the glass. Assuming your height is 1.50 m, and that
the eyes are located 0.1 m below the top of the head

(a) What is the distance between the spot and the floor?

(b) What is the minimum amount of mirror needed to see your entire image?

2. The attempt at a solution

I have correctly solved part (a) using a scaled diagram; however, I am having a hard time understanding part (b). This is because, logically, wouldn't your position, relative to the mirror dictate the amount of mirror needed to see the entire image? If someone could please point me in the right direction. Thank you.
 
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  • #2
Speedking96 said:
This is because, logically, wouldn't your position, relative to the mirror dictate the amount of mirror needed to see the entire image?
Draw a diagram. Hint: If you stand a distance "d" from the mirror, how far away is your image.
 

1. What is a plane mirror?

A plane mirror is a flat, smooth and reflective surface that reflects light rays in a predictable manner. It is typically made of glass or polished metal and has a reflective coating on one side.

2. How does a plane mirror work?

A plane mirror works by reflecting light rays at the same angle that they hit the surface. This follows the law of reflection, which states that the angle of incidence (incoming light ray) is equal to the angle of reflection (outgoing light ray).

3. What are the properties of images formed by a plane mirror?

The properties of images formed by a plane mirror are that they are virtual (cannot be projected onto a screen), upright, and the same size as the object. They also appear to be located behind the mirror at the same distance as the object is in front of the mirror.

4. Can a plane mirror form a magnified or inverted image?

No, a plane mirror can only form a virtual image that is the same size and orientation as the object. It cannot form a magnified or inverted image, unlike curved mirrors.

5. What are some practical applications of plane mirrors?

Plane mirrors have many practical applications, including use in rear-view mirrors, dressing room mirrors, and optical instruments such as telescopes and microscopes. They are also used in everyday objects like compact mirrors and reflective surfaces in buildings and vehicles.

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