Physics, 02.09.2019 20:20 andybiersack154

When looking at objects various distances away from you, your eye must create an image at the back of itself (at the retina). since your eye does not change size when looking to different dis tances, you must change the shape of the lens located at the front of your eye to make a clear image of different object distances at the same image distance. your near point is the shortest distance from the lens in your eye to an object for which you can make a clear image on your retina. a human with good vision will have a near point of 25 cm. the average eye length from front to back is 24 mm. assume that your lens is at the front of your eye, the lens is a spherical thin lens, and that your eye is made of air except for the lens. a) when looking at an object placed at her near point, what is the focal length of an average hu- man's lens? b) what is the focal length of her lens when looking at the moon? (hint: the moon is really far away) c) hyperopia occurs when your eye is too short. the lens is still limited to the same range curvatures. if somebody has an eye length of only 23 mm, what is their near point? d) you are an eye doctor in charge of prescribing glasses for this hyperopic person. if glasses rest 2.5 cm from the eye, what focal length should you prescribe to correct their near point?

Answers: 1

Show answers

Another question on Physics

Physics, 21.06.2019 22:30

The law of conservation of energy states that energy cannot be created or , energy can be from one substance to another. the first blank is ' destroyed ' and for the second blank is ' transferred '

Answers: 1

Answer

Physics, 22.06.2019 03:00

An internally reversible refrigerator has a modified coefficient of performance accounting for realistic heat transfer processes of where qin is the refrigerator cooling rate, qout is the heat rejection rate, and is the power input. show that copm can be expressed in terms of the reservoir temperatures tc and th, the cold and hot thermal resistances rt,c and rt,h, and qin, as where rtot rt,c rt,h. also, show that the power input may be expressed as 1.39 a household refrigerator operates with cold- and hot-temperature reservoirs of tc 5 c and th 25 c, respectively. when new, the cold and hot side resistances are rc,n 0.05 k/w and rh,n 0.04 k/w, respectively. over time, dust accumulates on the refrigeratorâ€™s condenser coil, which is located behind the refrigerator, increasing the hot side resistance to rh,d 0.1 k/w. it is desired to have a refrigerator cooling rate of qin 750 w. using the results of problem 1.38, determine the modified coefficient of performance and the required power input w under (a) clean and (b) dusty coil conditions. internally reversible refrigerator qout qin w high-temperature reservoir low-temperature reservoir th th,i tc,i tc high-temperature side resistance low-temperature side resistance w qin th tc qinrtot tc qinrtot copm tc qinrtot th tc

Answers: 2

Answer

Physics, 22.06.2019 05:50

There are two routes similar in terrain; however, one route has an incline of approximately 28 degrees, and you must decide on which route to take. what is the maximum road grade that your fully loaded ecv can climb?

Answers: 2

Answer

Physics, 22.06.2019 11:20

Wave functions describe orbitals in a hydrogen atom. each function is characterized by 3 quantum numbers: n, l, and ml. if the value of n = 2: the quantum number l can have values from to . the total number of orbitals possible at the n = 2 energy level is .

Answers: 3

Answer

You know the right answer?

When looking at objects various distances away from you, your eye must create an image at the back o...

Questions