Reading Quiz

Question 1:

Answer:

1. I'm a little confused about the last kind of ray diagram we drew, where do was very small. It made sense to me at the time, but I'm not sure I would be able to draw a diagram like it on my own, so it would be helpful to go over another type of example like that in class.
2. I'm okay with Monday's material.
3. none
4. I don't really understand why the Di and the Do vary so differently. It seems like if the focal distance is constant, they should both vary at the same rate. Also, how exactly does refraction work?
5. nothing at this time.
6. nothing, the lab was really fun
7. I think I understand all that we covered on monday
9. Nothing in particular.
10. I understand everything from the lab and class Monday.
11. I think I am ok with the material from Monday.
12. I think I'm alright with past material.
13. I had no problem with any of the material from Monday's Class
14. Why does the real image get flipped upside down (opposite orientation of the object) when looked at through a lense? The toy hardrive lab: how to graph binary (N and S) arrangements.
15. None
16. think im good
17. none
18. --
19. I think I'm caught up.
20. What is the difference between Rayleigh scattering, refraction, and dispersion?
21. nothing, thanks

Question 2:

Answer:

1. We learned in lab today that a curved lens, or a lens with a high diopter, has a shorter focal length than a flat lens, or one with a low diopter. In a curved lens, light passing through the top of the lens is bent downward while light passing through the bottom is bent upward; these rays converge at a point where the image appears. In a flat lens, these rays do not converge as they do in a curved lens (do they not converge as soon or just not at all? not sure about this), which accounts for the flatter lens having a longer focal length, or the distance between a lens and its real image.
2. The lens with a high diopter has the shorter focal length. This is because this lense is more curved, and therefore bends the light more sharply. If the light bends more sharply, the rays will converge closer to the lens, meaning the focal length is smaller.
3. The lens with the high diopter has the shorter focal length because the lens bends the light more sharply than the lens with the low diopter. It's a more significant change and is worn by people who's vision is worse.
4. A high diopter lens, or a very curvy lens, has a shorter focal length. You can imagine that a lens with more extreme changes in angle would cause more extreme changes in the image you see as well.
5. A very curved lense(high diopter) has a shorter focal length. The diverging lenses bend light rays apart and therefore has a negative focal length.
6. The lens with the high diopter with have the shorter focal length. Because it curves more, it will bend the light rays together closer to the lens.
7. A higher diopter has a shorter focal lenght. This is because a more curved lense, bends the light rays more dramatically than a flat lense, which makes their rays converge at a closer point to the lens.
8. The shorter focal length comes from the more curved lens. The amount of refraction from the lens that is more curved is greater, so the point where the light rays intersect is closer.
9. A lens with a high diopter has a shorter focal length because the parallel rays are bent more and diverge more quickly to the focal point.
10. A high diopter lens has the shorter focal length. Since the lens is more curved, the light gets bent at a greater angle, which means the rays will converge after a shorter distance from the lens.
11. The curved lens with a high diopeter has the shorter focal length- since it is curvier, the refracted rays will be at more drastic angles and converge at a closer point providing for a shorter focal point.
12. A lens with a high-diopter would have a shorter focal length, because a curved lens bends the light that passes through it more strongly, and the rays intersect quickly to create a focused real image.
13. The lens with the high dioper (and curved lens) would have the shorter focal length because the curvier the lens is, the more bent the ray will be and the closer to the lens the focal point will be.
14. The high diopter lens would have a shorter focal length because just like seen in the lab, the curvier lens converges the object (rays of light) at a greater angle than a very flat lens does, hence the focal length (distance between the lens and the real image) is very short.
15. The high diopeter lens has the shorter focal length because curved lenses converge rays closer to the lens than thinner ones.
16. a lenz with a high diopter has a shorter focal length because a more curved lenz bends the light more.
17. One with a high diopter had a shorter focal length. This is because it is a converging lens, and the light is bent.
18. I believe the lens with a high diopter has a shorter focal length because the lens will be curved more, and that decreases the focal length. If a lens is curved more, the light bends more sharply and will focus within a shorter distance.
19. a high diopter lens would have the shorter focal lengh because its more curved lens bends the light more aggressively than the flatter lens.
20. A high diopter lens would have a shorter focal length because it would be able to bend the light rays a lot more than the flatter lens.
21. The high diopter would have a shorter focal length because the more curved a lense is the more severely the light is bent after going through the lense so this makes the light intersect closer to the lense making a shorter focal length.

Question 3:

Answer:

1. di = 0.0175 m
2. Using the thin lens equation, the real image will form 35.6 mm away from the lens.
3. 35.6 mm
4. We can use the equation "inverse of focal length equals inverse of object distance plus inverse of image distance" to find the location of the real image. By subtracting the inverse of 2 m (2,000 mm) from the inverse of 35 mm, we get a real image distance of 35.6 mm from the lens.
5. 2.035m
6. .036 m
7. 1/35 = 1/2000 + 1/di di = 35.62 mm
8. 3.6 cm
9. 1/.035 = 1/2 + 1/x ===> x = .0356 m or 35.6mm
10. 1/.035m = 1/2m + 1/x x=.0356m, so image forms .0356m or 35.6mm from the lens.
11. 35.6 mm
12. .03562 meters away from the lens.
13. di = .35cm
14. use the lens equation: 1/focal length = 1/object distance + 1/image distance. 1/35mm = 1/2m + 1/image distance so image distance = 35.62mm
15. 35.6 mm from the lens
16. 1/.035m = 1/2m + 1/x x= .0356 m ....= 35.6 mm.
17. 1/3x10^-6 = 1/2m + 1/i i = 3.5x10^-5
18. 35.6 mm away from the lens
19. The real image will form 2.12 meters away, but the sign is negative so I think that means it won't form at all?
20. The real image of the flowers form about 35.6 mm away.
21. .035m from the lens

Question 4:

Answer:

1. A near sighted person is unable to see objects that are far away; the lens sytem of the eye(s) has too short a focal length and the images of viewed objects form too close to the front of the eye (as opposed to too far from the front of the eye, as in a far sighted eye). A diverging lens has a negative focal length and bends the rays of light from an object so that the rays diverge more rapidly--I understand the explanation up until this very last point.
2. The lens of the eye of a near-sighted person focuses light in front of the retina, therefore in order to correct their vision the real image formed must be shifted back to the retina. In order to increase the image distance the light that the lens of the eye receives must be more spread out, so that it can bend the light to converge on the retina. A diverging lens bends light rays apart, therefore this is the type of lens used.
3. A near-sighted person's vision focuses before it hits her retina and blurs between the focal point and retina, so what the person sees is out of focus. The diverging lens increases the focal length of the projected image and focuses it on the lens wearer's retina.
4. A diverging lens creates a negative focal point, which ends up "subtracting" from the focal point that the person experiences, which is too far behind the retina. By "subtracting" from the persons' eyes' natural focal point, the diverging lenses bring the focal point neatly onto the retina, where the eye can then see them clearly.
5. A diverging lens bends light rays apart and therefore has a negative focal length.
6. When a person is near sighted, they cant focus on distant objects because their lens has too short a focal length. A diverging lens bends light rays away. The rays will then appear to be coming from a closer object, and the person can focus on it.
7. A person who is near-sighted has too short a focal lenght to focus on objects that are far away. To compensate for this, a diverging lens bends the light rays apart and increases the focal length.
8. the lenses in the person's eyes converge the light rays too much. therefore, if then light rays are already diverged a lot, when the person's eyes converge the light rays, the fact that the light rays enter the eye very diverged makes the over convergence of the person's eye give them the correct view.
9. A diverging lens bends the nearly parallel rays of light more rapidly so that the rays appear to come from a much nearer object. Nearsighted eyes are able to focus them properly and thus their vision is corrected.
10. With a nearsighted person, the image forms before the rays hit the retina. By using a diverging lens, it spreads the rays out so the real image will form further from the lens, thereby moving the focal point to the retina, so the object is clear.
11. A diverging lens bends rays from a distant object so that the diverge more rapidly and focus the image on the retina as it should be, rather than forming an image too close to the front of the eye.
12. A near-sighted person's vision is corrected with a diverging lens because her lens system has too short of a focal length; its lens bends light too strongly to focus on an object. A diverging lens shifts the real image backward so that it focuses on the retina.
13. A near-sighted person's vision is corrected with a diverging lens because a newar-sighted person's eye bends light too strongly to focus on a distant object, therefore the real image forms before the retina. A diverging lens shifs the real image backward so that it focuses on the retina.
14. Since a nearsighted person's eye bends light too strongly to focus on a distant object, the real image forms behind the retina. So a diverging lens is used to shift the real image backward so that it focuses on the retina.
15. diverging lenses shift the real image backward so that it focuses on the retina
16. A near sighted eye bends the light too sharply so that an image forms before the retina. The diverging lens spreads the lightwaves out so that the real image shifts backwards and shows up on the retina.
17. Because a diverging lense bends light rays apart and therefore has a negative focal length. It bends the parallel rays of light from a distant object so that they diverge more rapidly. This allows the eye to focus because the rays look like they come from a nearer object.
18. A diverging lens makes a far away object appear closer so that a nearsighted person is able to focus on it.
19. Because the the eye is bending light too strongly so its out of focus when it reaches the retina, but a diverging lens spreads the incoming light before it hits the eye and so when the eye compresses it too much the two effects cancel out and it looks normal.
20. Well a person who is near-sighted is unable to focus on distant objects because the lens in his eye has too short of a focal length. So what happens is real images of those distant objects form too close to the front of his eye and the light has already begun to spread apart by the time it reaches his retina. Thus, a diverging lens bends the almost parallel light rays from a distant object so that they diverge more rapidly. Actually a diverging lens has a negative focal length that creates a nearby virtual image in which his eyes are able to focus on.
21. A diverging lense bends light rays apart, this makes rays that come from a distant object seem like they came from a closer object or closer virtual image, this allows the eye to focus on them better.

Question 5:

Answer:

1. See answers to 1 and 2. I'd also like to spend time further discussing converging and diverging lenses as they relate to far sighted and near sighted vision, respectively.
2. I wasn't confused by this section of the reading.
3. virtual images-- Also, can you talk about what we'll cover on the final?
4. I have the basic idea, but don't understand all the subtleties of "depth of field".
5. How does a lens focus? Figure 15.1.5
6. I didnt really get why a zoom lens needed three groups on lenses to work.
7. I understand all of the concepts in this reading
9. This was such an interesting section because there are so many real world examples (zoom on a lens, how glasses work, how eyes work, etc). However I'm still a little unsure about some of the basics of lenses like why some objects are in focus and others are not.
10. Where it discussed using multiple lenses for color focusing in the camera.
11. Can we go over the nearsighted/farsighted problems and how they are solved with lenses?
12. I'm clear with the concepts and equations.
13. I would like to spend more time in class discussing the difference between a diverging and converging lens and how cameras transform the image into an actual picture (on paper).
14. Why does the real image flip?
15. none
16. i want to go over the focal length equation if i got this 3 wrong
17. none
18. I don't completely understand focal lengths. I understand how it relates to image and object distances, but how is it different from the image distance?
19. I think I understood all this.
20. I think I understood everything from this section.
21. Nothing, thanks