Solving Plane Mirror Question: How Far is the Flagpole?

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In summary, the question asks for the distance from a 900cm squared plane mirror when held 45 cm from the eyes, to a flagpole with a length of 8.5 m. The solution involves converting the mirror's area into its height and using triangles to find the answer, while ensuring consistency with units.
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dev-hud
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If you hold a 900cm squared plane mirror 45 cm from your eyes and can just see the full length of an 8.5 m flagpole behind you, how far are you from the pole.



I am doing mirror/lens questions and for some reason this one stumps me. I am assuming that the 8.5 m has to be changed to cm. However, i have been dealing with questions of radius of curvature and focal length and then this one seems really easy but it has stumped me? can anybody help please?
 
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dev-hud said:
If you hold a 900cm squared plane mirror 45 cm from your eyes and can just see the full length of an 8.5 m flagpole behind you, how far are you from the pole.



I am doing mirror/lens questions and for some reason this one stumps me. I am assuming that the 8.5 m has to be changed to cm. However, i have been dealing with questions of radius of curvature and focal length and then this one seems really easy but it has stumped me? can anybody help please?

Convert the area you are given for the mirror into its height. Then use a sketch to figure out the triangles to get to the answer. And yes, you need to be consistent with your units. I'd put everything in mks, myself.
 

FAQ: Solving Plane Mirror Question: How Far is the Flagpole?

1. How do I solve a plane mirror question about the distance of a flagpole?

The first step in solving a plane mirror question about the distance of a flagpole is to draw a diagram. Label the mirror, the flagpole, and the observer's location. Also, mark the angles of incidence and reflection.

2. What is the formula for solving a plane mirror question about the distance of a flagpole?

The formula for solving a plane mirror question about the distance of a flagpole is d = (m x D)/2, where d is the distance of the flagpole, m is the measured distance between the observer and the mirror, and D is the distance between the mirror and the flagpole.

3. How do I determine the measurements needed for the formula?

You will need to measure the distance between the observer and the mirror, as well as the distance between the mirror and the flagpole. These measurements can be done using a ruler or measuring tape.

4. What if I do not have access to the actual measurements?

If you do not have access to the actual measurements, you can use a scale drawing. Simply draw a scale diagram of the situation, with each unit representing a specific distance, and use the scale to determine the measurements needed for the formula.

5. Are there any other factors that need to be considered?

Yes, you also need to take into account any vertical displacement between the observer's eye level and the base of the mirror. This can be done by measuring the height of the observer's eye and subtracting it from the measured distance between the observer and the mirror.

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