# What Does A Spider Mean

Decent Essays

8. “A person in a dark room looking through a window can clearly see a person outside in daylight, whereas the person outside cannot see the person inside. Explain.

This can be related to the angles of light from the room compared to outside. On the inside the interior setting is blocking the room from being illuminated by the sun, so the angles of light are limited to a spot close to the window. A person standing close to the window may be able to be seen, but if they go back then they will not be illuminated, and will not be seen. A person looking out can see clearly because there are no objects blocking the sun from illuminating the person and their soundings.

18. “What is wrong with the cartoon of the man looking at himself in …show more content…

You are behind the spider, 50 cm from the mirror. Show that the distance between your eye and the image of the spider in the mirror is 70 cm.” When it refers to “the image of the spider on the mirror,” it is really asking for the distance between your eyes and the mirror. If a spider is 20 cm behind the mirror, and you are 50 cm away from the spider, then adding those two distances will give the total, which is 70 cm just as the problem says.

8. “The quantitative way of relating the object distance d-sub o with the image distance d-sub i for a lens given by the then-lens equation (1/d-sub o)+(1/d-sub i)=1/f. Rearrange to show that d-sub i=(d-sub o)(f)/(d-sub o)-(f)”

This is an algebra problem involving an equation with fractions. I solved it on paper and attracted the work, but it should be noted that I substituted d-sub o with a, d-sub i with b, and f with c. To briefly explain how I solved it, I did the following:

-found a common denominator of abc, which led to the two fractions on the left side being combined into one.
-canceled out ab/ab on the right side,
-cross-multiplied to get abc=bc^2+ac^2
-factored out c^2, then divided it by both