Recent content by carnivalcougar

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    Statistical error analysis of Geiger counter?

    I attached pictures of the question with the equations typed out so they will definitely be correct. We also did not learn Poisson processes.
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    Probability of counts from the counting rate of a radioactive sample?

    We were not told what a Poisson process is, just that the standard deviation will equal to \sqrt{navg} where navg is the average number of counts, n. If there are 468 counts per minute then the average count rate /10s will be 81 and the standard deviation of that will be 9. So you would get less...
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    Statistical error analysis of Geiger counter?

    1. Homework Statement An average value of N measurements is defined as: ravg = 1N ∑ ri where i = 1 and it sums up to N measurements By using this expression in the master formula for a general function z = (x1, x2,...) error propagation, we find the δravg error propagation: (δravg)2 =...
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    Mass attenuation problem, protecting the lunar base against radiation?

    For this problem, I = I˳e-µx I = 1 and I˳ = 1.5 x = 4m + some distance μ = no idea They do not give the half value layer λ which is related to μ by μ = ln2/λ Therefore, I'm not seeing how to solve the problem. If you start with I = 1.5 , I˳ = original intensity before the...
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    Mass attenuation problem, protecting the lunar base against radiation?

    Would this just be 5.333m? if 4m attenuates to 1.5x Earth radiation, then 1/3 more regolith would attenuate to 1x Earth radiation. 4x(1/3) = 1.333 and 4+1.333 = 5.333
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    Mass attenuation problem, protecting the lunar base against radiation?

    Homework Statement To protect the lunar base against space and sun radiation, astronauts covered it with 4m thick layer of regolith (moon soil). However, they found that they level of radiation was still 50% higher than on the Earth's surface, which they want to match. How many more meters of...
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    Probability of counts from the counting rate of a radioactive sample?

    Homework Statement The average counting rate of a radioactive sample is 486 cpm (counts per minute). Find the probability that in any given 10s interval one gets less than 72 counts. Is this the same as the probability of getting less than 72 X 6 = 432 counts in 60s? Homework Equations...
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    Archived Relative error of a geiger counter?

    Homework Statement A geiger counter measures 750 counts in 5 min a) determine the average counting rate and the standard deviation of the counting rate. b) find the relative error c) How long would you want to count to get a relative error of 1%? Homework Equations standard...
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    Should optical cables be water tight? Geometric optics

    Homework Statement Explain the physical principle of total internal reflection used by optical cables. Calculate the critical angle of incidence that corresponds to a refracted angle θair = 90 Next, calculate the critical angle for a bare glass fiber submerged in water nH2O = 1.33...
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    Irradiance of sun in an image?

    I think that the radius of the lens is equal to 2f which would make the radius .4m. Therefore, the area of the lens is .50265m^2. Multiply this by 500 and this tells you the power on the lens which is 251.327W. The area of the image is 1.099X10^-7m^2 which is from ((.000187m)^2(pi)). Therefore...
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    Irradiance of sun in an image?

    I'm not sure how to find the diameter of the lens which is what I need to find the total power falling on the lens
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    Geometric optics - thickness of acrylic ?

    Oh yeah that would have been easier. Either way I got 7.0852 for the hypotenuse. Then I used the law of sines on the triangle that has the same hypotenuse but the opposite side is the normal line, and therefore, the thickness of the acrylic to find what the thickness of the acrylic is. This came...
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    Geometric optics - thickness of acrylic ?

    Would I then use the law of sines to find the hypotenuse of this triangle? Thanks!
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    Geometric optics - thickness of acrylic ?

    I think it would be south of the X axis. Which would give me the angle I need to find the third angle of the triangle?
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