Lab 13: Reflections and Mirrors

Lab 13: Reflections and Mirrors

In lab 13 we experimented mirrors to see how they reflect images and how reflection truly works. Reflections are based on how light reflects off of the reflective surface of a mirror. This causes the light to then be bounced equal arc of which some will bounce into a human eye to be perceived and viewed. This equal arc also causes the light to occupy a fixed point, and based on the mirrors position causes how we can move into and out of view of the mirror. Throughout our experiments we found that these points will be fixed and will perceive the same amount of the person no matter how far away the person is from the mirror, if it can’t see your legs at 5 ft away, it can’t see them 10-15- or even 20 ft away. As a result we were asked, what is the minimum size we can have in a mirror for it to be able to see our entire body and reflect it back at us.

To figure this out we realized that the point on the mirror that we needed to adjust was the midpoint, the area where the light bounced off of the mirror and back at us. We calculated that since the angle was always the same we could use a midpoint on our own body’s dimensions to figure out how to calculate the size. Because the rays always had to reflect to our eyes, we measured the distance from our toes to our eyes, from our shoulders to the opposite eye, and from the top of our heads to our eyes. I am personally 6'4 and had the following calculations, 182 cm toe to eyes, 8 cm top of head to eyes, and roughly 40 cm shoulder to opposite eye. We then halved this data to use their midpoint, and then added the measurements that would be used to find the mirrors dimensions, namely the head and toe points for height, and the shoulder points for width. After computing this i found that for a mirror to be properly sized for me it would need to be 95 cm tall and 40 cm wide.

Errors

As usual we did have plenty of opportunities for error. One major problem we could have had is problems measuring and rounding, as all we had was a yard stick that had to be flipped and remeasured to measure our overall height. We also had problems rounding and would commonly round to the nearest centimeter for easy use, which could provide some problems given that the dimensions needed to be exact, but a few millimeters will not make a noticeable or major difference.