An object placed in front of a plane mirror

In summary, in order for the observer to see the image of the object placed 1m in front of a plane mirror, they would need to focus their eyes at a distance of 4m (3m + 1m) because the image appears to be 3m behind the mirror.
  • #1
Kathi201
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An object is placed 1m in front of a plane mirror. An observer stands 3m behind the object. For what distance must the observer focus his eyes in order to see the image of the object?

My guess is that the observer would have to focus their eyes 3m in order to see the image because when the object is reflected off the mirror it is reflected at the same angle so therefore it reflects back at that same 1m spot. I am not quite sure if this is right though.

Any help would be appreciated!
 
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  • #2
He would need to focus at 3m to see the object itself, but not it's image. The image does not focus at the same point as the object. (If this was the case we wouldn't see anything in the mirror!)

The image of the object is actually a virtual image that appears to be behind the mirror. How far behind the mirror does the image seems to be?

Add this to the distance the observer is from the mirror, and you have your answer.
 
  • #3


I can provide you with a more accurate and detailed explanation. When an object is placed in front of a plane mirror, its image is formed behind the mirror at the same distance as the object is from the mirror. In this case, the object is placed 1m in front of the mirror, so its image will be formed 1m behind the mirror.

The observer, who is standing 3m behind the object, will see the image as if it is 3m behind the mirror. This is because the light from the object travels 1m to the mirror, reflects off the mirror, and then travels another 2m to reach the observer's eyes. This creates the illusion that the image is located 3m behind the mirror.

Therefore, in order to see the image clearly, the observer will need to focus their eyes at a distance of 3m, as this is the apparent distance of the image from the observer's perspective. This is known as the virtual image distance.

It is important to note that the distance at which the observer focuses their eyes does not affect the location of the image. The image will always be formed at a distance equal to the distance between the object and the mirror. Focusing the eyes at different distances will only affect the clarity and sharpness of the image.

I hope this explanation helps to clarify any confusion. If you have any further questions, please let me know.
 

1. How does a plane mirror reflect an object?

A plane mirror reflects an object by bouncing off light rays at the same angle that they hit the mirror. This creates a virtual image that appears to be behind the mirror at the same distance as the object is in front of the mirror.

2. Will the image in a plane mirror be the same size as the original object?

Yes, the image in a plane mirror will be the same size as the original object. This is because the rays of light are reflected at the same angle, creating an image that is the same size and shape as the object.

3. How is the orientation of the image in a plane mirror different from the orientation of the object?

The orientation of the image in a plane mirror is reversed from the orientation of the object. This means that the left side of the object will appear to be on the right side in the mirror image and vice versa.

4. Can you see the image in a plane mirror from any angle?

Yes, you can see the image in a plane mirror from any angle as long as you are able to see the mirror. However, the angle of reflection will change depending on the angle at which you are viewing the mirror.

5. Are there any differences between a plane mirror and a curved mirror?

Yes, there are differences between a plane mirror and a curved mirror. A plane mirror reflects light rays at the same angle, whereas a curved mirror reflects light rays at different angles, resulting in a distorted image. Additionally, a plane mirror creates a virtual image, whereas a curved mirror can create both virtual and real images depending on the curvature.

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