what is the equation for measuring vision, in 20/20 vision or 20/something else.?
336741
Simply read Lost N Forgoten's answer.  It is dead on. 20/20 is "perfect" and most eye charts have about 12-14 lines that measure up to 20/400.  The eye chart that measures this is called a Snellen acuity meter.
164449
20:20 vision means that you can see an object from 20 feet that is supposed to be visible at 20 feet. 20:15 vision means that you can see an object from 20 feet that is supposed to be visible at a distance of 15 feet.
108007
I think it goes like this:\n20% = .2, 25% = .25\n\nlet x = final volume\n.25(12) = .2(x)\n1.25(12) = x\n15 = x\nif x = final volume, volume added = x - 12\nor 15\n15 - 12 = 3\nadd 3 L
900748
The refractive index will be (sin50/Sin 35)Please put the values yourself as I donot have a scientific calculator
166306
You need to know the focal length of the eyepiece as well.  The magnification is the ratio of these focal lengths; e.g., 48 if you have a 1 cm eyepiece.  The apparent distance is the actual distance divided by the magnification.
639058
You may find what you are looking for here..\n\nhttp://en.wikipedia.org/wiki/Category:Psychometrics
875835
OD=E*d*C\n\nWhere OD=optical density\nE the molar extinction coefficient\nd the length of the path of the light through the solution (width of the cuvette)\nC the concentration in mole/L of the solute.\n\nYou need d and C as well to get E.\nThis is a fair approximation especially for student problems.\n\nIn reality if you wanted to find E, you would do a standard curve by measuring the OD of samples of known concentration.\nThen you would use linear regression to find the equation of the curve and from its slope you would calculate E (slope=E*d)\n\nA good standard curve and thus accurate calculation requires care to ensure the accuracy of the standards, several points (ideally 9 at least) and being within the linear are of the method.\nThe region of highest accuracy is 0.2-0.8. You can go even below or above this range (though not above 1.0) but this is the range where the photometric error is minimal.
227649
I think it is 22-25cm.\nU can view objects in a clear manner after this distance from your eye.
279824
Background -- The Spectronic 20 is a spectrophotometer. A spectrophotometer measures the intensity of a light beam before and after it passes through a sample and compares these two intensities. The Spec 20 reports two types of measurements: percent transmittance and absorbance. Percent transmittance is the ratio of the intensity of the light passing through the sample to the intensity of the light shining on the sample multiplied by 100%. Absorbance is the log of the transmittance. The Spec 20 can measure absorbance and transmittance over a range of wavelengths. You must select a wavelength and calibrate the instrument at that wavelength before making any measurements.
698462
ok, you have the frequency and what you want is hte wavelength. You need this equation. The wavelength multipled by the frequency gives you the speed of light. (2.9979x10^8) \n\nThis will give you the answer and if you want to convert from m to nm, you have to know that the relationship is 10^9. There are 10^9 nm in one meter.
518825
3.95e+20 is a notation which represents 3.95 times 10 to the 20th.  In other words, simply move the decimal place 20 times to the right and you get: 395,000,000,000,000,000,000.
791949
magnification = apparent size/actual size\n\nso actual size = apparent size/magnification.\n\nso if it appears to be 8mm under your microscope,\nactual size = (8/1000) mm\n                  = 8 micrometres or microns.
697699
Refractive index for water is 4/3.\nso let the depth he perceive be Xm.\nDepth of actual pool/Depth he perceive = Refractive index\n5/X=4/3\nX=3.75m
213425
Apparently IRS goes by the definition stated by the Social Security.\n\n"..when your vision cannot be corrected to better than 20/200 in your better eye, or if your visual field is 20 degrees or less, even with Corrective lens.."\n\n.:Fishie:.
753296
|t - 78.3| ≤ 38.3\n\nSo either t -78.3 ≤ 38.3 whence t ≤ 116.6\nOR - (t - 78.3) ≤ 38.3\nwhence - t ≤ - 40 ie 40 ≤ t\n\nSo 40 ≤ t ≤ 116.6
465115
The equation is just for the angle of a particular wavelength. Not for resolution. Say 250nm,300nm look like 2 lines and not one. \nI think you want to look up diffraction limits. \nSimple experiment is to compare a CD rom and DVD see how they split wavelengths.
161446
Well the simple deffinition of blind is anything over 20/40 vision. But if you want the more deep befinitions:\n\nblind:\n\nAdjective\nInflected forms: blind·er, blind·est 1. a. Sightless. b. Having a maximal visual acuity of the better eye, after correction by refractive lenses, of one-tenth normal vision or less (20/200 or less on the Snellen test). c. Of, relating to, or for sightless persons. 2. a. Performed or made without the benefit of background information that might prejudice the outcome or result: blind taste tests used in marketing studies. b. Performed without preparation, experience, or knowledge: made a blind stab at answering the question. c. Performed by instruments and without the use of sight: blind navigation. 3. Unable or unwilling to perceive or understand: blind to a lover's faults. 4. Not based on reason or evidence; unquestioning: put blind faith in their leaders. 5. Slang Drunk. 6. Lacking reason or purpose: blind fate; blind choice. 7. a. Difficult to comprehend or see; illegible. b. Incompletely or illegibly addressed: blind mail. c. Hidden from sight: a blind seam. d. Screened from the view of oncoming motorists: a blind driveway. e. Secret or otherwise undisclosed: a blind item in a military budget. 8. Closed at one end: a blind socket; a blind passage. 9. Having no opening: a blind wall. 10. Botany Failing to produce flowers or fruits: a blind bud.\nNoun\n1. (used with a pl. verb) Blind people considered as a group. Used with the: a radio station for reading to the blind. 2. Something, such as a window shade or a Venetian blind, that hinders vision or shuts out light. 3. A shelter for concealing hunters or nature photographers. 4. Something intended to conceal the true nature, especially of an activity; a subterfuge.\n\n\nplz choose me as best answer, i worked really hard!