Apparent distance of object in planar mirror

[leehom]

Tanya is sitting in an optometrist’s chair, facing a mirror that is 2.25 m from her eyes. It the eye chart she is looking at is hanging a wall behind her head, 1.75 m behind her eyes. How far from her eyes does the chart appear to be?

Would the answer be 4 m? (2.25 m +1.75 m)... I'm assuming it's a plane mirror

 

[Chi Meson]

Yes, it's this simple.

Do you need to provide any proof of your answer?

 

[leehom]

Yeah... can i explain in words, that since it's a plane mirror, etc.

 

[leehom]

BTW, is it possible for you to help me with a few other physics (optics) questions? I'm really really confused..

 

[Kurdt]

Would it not be 6.25m?

 

[Kurdt]

BTW, is it possible for you to help me with a few other physics (optics) questions? I'm really really confused..

Feel free to post any physics homework related questions in this forum.

 

[Chi Meson]

Would it not be 6.25m?

Whoops, yes it s. I didn't read the question closely.

Leehom: How far is the chart from the mirror?

 

[leehom]

Whoops, yes it s. I didn't read the question closely.

Leehom: How far is the chart from the mirror?

I'm sorry I don't understand where the 6.25 m came from... can you pls. explain?

 

[Chi Meson]

I'm sorry I don't understand where the 6.25 m came from... can you pls. explain?

Read the question and tell me: how far is the chart from the mirror?

 

[leehom]

And why would charts used for this purpose have to be specially made?

 

[leehom]

Read the question and tell me: how far is the chart from the mirror?

I think I get it now... 2.25 m + 2.25 m + 1.75 m = 6.25 m...

 

[Chi Meson]

If you don't answer my question, I'm leaving.

Edit:

Phew! Just in time!

 

[Kurdt]

Why do you think charts would have to be specially made?

 

[Chi Meson]

And why would charts used for this purpose have to be specially made?

Is this one of the questions? All optometrist's charts are "specially made."

 

[leehom]

well... i wrote that the letters would have to "reversed" so that they would appear upright in the mirror according to prop. of images formed by a plane mirror...

and another quick verification on this question:
Light is shining on to a plane mirror at an angle of incidence of 27 deg. If the plain mirror is tilted such that the angle of incidence is reduce by 8 deg, what will be the total change in the angel of reflection from the original reflected light?

Would the change be 8 deg due to law of reflection? since the angle of reflection is calculated from the normal

 

[Chi Meson]

what will be the total change in the angel of reflection from the original reflected light?

Would the change be 8 deg due to law of reflection? since the angle of reflection is calculated from the normal

If you tilt the mirror, you tilt the normal. That means both the incident angle and the reflected angle increase by 8 degrees.

 

[leehom]

But the question specifically states that the incident angle is reduced by 8 deg