What is Test: Definition and 1000 Discussions

Homework Statement A planet has a gaseous atmosphere with a density of 0.1 g/cm³. The planet itself completely consists of liquid methane with a density of 0.4 g/cm³ and has a radius of 3800 km. A test balloon is dropped onto this planet, which consists of a helium spherical balloon (1 m³, mass...

A high-performance diesel engine explodes into pieces while being run on a dyno test.

Apologies if this is a stupid question, so for e.g, in a Schwarzschild space-time we look at ##R^{abcd}R_{abcd} ## (we seek some scalar quantity that blows-up and can not use ##R##as we are looking at vacuum solutions so we know this is zero) The reason we seek a scalar is because it is the...

Hi, I made the following command in MATLAB to test for the following: \begin{equation} \langle T\psi,\phi\rangle=\langle \psi, T\phi\rangle \end{equation} %Self-adjoint test syms x a = (diff(exp(-x^2)))*exp(-2*x^2) b = (diff(exp(-2*x^2)))*exp(-x^2) W = int(a, x) P = int(b, x) O=W-P and it is...

Hi I would like to know if there is any physical or medical scientific tests I can take to know/confirm my energy levels/body energy levels and will level when it comes to motivation. the reason for wanting to take these tests is that I have a severe mental brain neurological disability known...

Hi, I'm doing a pressure test with a liquid medium. I have a fixed volume and I know the pressure drop, and temperature change - how do I calculate volume of liquid lost in a leak?

I've spent some time setting up my simulation of a photonic EPR experiment and came up with an exact joint probability distribution for the outcomes ##P_{xy}(\alpha,\beta)##. To calculate the CHSH number we need the probability of a coincidence for each of the possible settings which becomes a...

Homework Statement Two computer software packages are being considered for use in the inventory control department of a small manufacturing firm. The firm has selected 12 different computing task that are typical of the kinds of jobs. The results are shown in the table below. At the 0.05 level...

Homework Statement I know that for both method are used to test the 2 group sample for a non-normally distributed population ... But , i am not sure the difference between them . Can someone explain the difference between them ? When to use sign test and wilcoxon signed rank test ? Homework...

Homework Statement In the photo above , H0 = the position of the plant doesn't affect the number of seeds in the pods . H1 = position of the plant affect the number of seeds in the pods The Attempt at a Solution This is a two -tailed test , am i right ? Referring to the normal distribution...

##f(x,y)## a critical point is given by ##f_x=0## and ##f_y=0## simultaneously. the test is: ##D=f_{xx}f_{yy}-(f_{xy})^2 ## if ##D >0 ## and ##f_{xx} <0 ## it is a max if ##D >0 ## and ##f_{xx} >0 ## it is a min ##D >0 ## is is a saddle if ##D =0 ## it is inconclusive, and ##f_x## and...

As the permanent magnet is magnetized by donut shape coil, thus field B = 0 outside. How can I know if seller screwed me or not?

Homework Statement ##\sum _{n=0}^{\infty }\:\sin \left(\frac{1}{n}\right)## Homework Equations The Attempt at a Solution Can I try comparison test by ##\left(\frac{1}{1+n}\right)<sin\left(\frac{1}{n}\right)## since ##\left(\frac{1}{1+n}\right)## diverges also...

Homework Statement So I am doing a project for statistics and wanted to apply a hypothesis test to see if there is a correlation between the number of years spent at my college and the number of services used. The services include library, recreational services, clubs, etc.. i sent out a survey...

Homework Statement I am modeling a 2D indentation test of pure Aluminum in ANSYS using non-linear analysis. The objective is to determine the minimum force required at the rigid indenter in order to achieve yielding of the Aluminum block. The indenter is 2 micrometers in width and is rigid...

Hello! (Wave) We want to find an efficient algorithm that checks whether an odd number is a prime or not. In order to obtain such an algorithm, one tests the congruence $(X+a)^n \equiv X^n+a$ not "absolutely" in $\mathbb{Z}_n[X]$, but modulo a polynomial $X^r-1$, where $r$ have to be chosen in...

i am stuck on question 12 I am trying to use the hypothesis testing 1 sample t test formula . the right answer is 338 but I can not get this

I use this when making exams for all my courses. It goes in the preable or the very beginning of the .tex file. Note the use of the commands, I also include commands imported by the file macros! Macros is simiply a .tex file defining your own commands. I have included in another post a list...

Homework Statement If the sum of a sub n to infinity (n=1) converges then the limit of n as n tends to infinity of an = 0 Homework EquationsThe Attempt at a Solution an =(a1+a2+...an)-(a1+...+an-1) = limit of an (n tends to infinity) = sn -s(n-1) =0 The area I'm confused is why do we assume...

Hi! I’m a physics undergrad and one of my first term courses is applied linear algebra. I knew exactly what to study for this midterm, so I practiced it over and over again until I was sure I was comfortable with it- went into the test and the exact same type of questions I studied and...

Homework Statement Homework Equations \overrightarrow{F} = \frac{1}{4\pi\epsilon_0}\frac{qQ}{r^2}\hat{r} The Attempt at a Solution I found to hard summarizing all forces directly adding each to other. The solution of this problem is only matter of drawing the 13-sided polygon and forces...

I was performing XRD earlier, and I came across this odd occurrence in the powders that were being inspected - After it was performed, the crystalline powder I had been testing had gone off color into this yellowish appearance (Originally was white). Upon disturbance, the powder become white...

I feel way in over my head. I've been telling people I'm going to major in physics, but I've actually never taken a physics course before. This is my first one. I was so excited to start this class, start the major. I was so excited about research and internships and what I'd be able to do with...

I always keep on taking the MBTI and I get INTP. What is everyone else's MBTI? http://www.humanmetrics.com/cgi-win/jtypes2.asp << Mentor Note -- INTP = Introverted iNtuitive Thinking Perceiving >>

I am aware that f-tests can be used to check the null hypothesis when comparing regression models if the models are nested. What I am confused about is if I can apply an f-test to compare the following, (and if so what is the best way) I have two regression laws Y = a1*X1 + a2*X2 + b Y =...

I am planning on taking SAT Subject test in Physics in few months, but I don't know which textbook is best to study all physics concepts that will be tested. I have a basic knowledge of algebra and almost none of calculus, as they didn't teach them back in high school, but I really want to...

Homework Statement "Let there be two point charges ##q_1=3.5μC## and ##q_2=-3.5μC## located at ##(0,0.3 m)## and ##(0,-0.3 m)## respectively. What force do these two charges exert on a test charge ##Q=4.5μC## at ##(0.4 m,0)##?" *title should read "due to two point charges"* <Moderator's note...

Hello gang! I am dealing with a new issue at work and I though you might give me some much useful insight. Im trying to fix a component to a plate and using 4 screws and rubber bushings to attach said plate to the firewall. The component is around 5-6 kgs and needs to held in place firmly but...

I know fusel alcohol is not an official term, and my chemistry is rusty, but is there an easy way to test for fusel alcohols in a primarily ethanol/water mixture? Basically, any alcohol that isn't ethanol? https://en.wikipedia.org/wiki/Fusel_alcohol

Dear moderator, if the thread is irrelevant to this forum section, please move it to the right section. Thanks.

Can anyone test for or give reference for lab testing white ginseng % purity? I can send sample by mail. Thanks, morrobay

I have a statistics problem that is probably not too difficult for someone who knows what they are doing, but I still need help with it. Here’s the scenario. There is a town with a highway built at the end of 2013. The mayor is concerned because of the number of traffic accidents on the...

If my professor tasked me with finding out where to find the materials for setting up an electromagnetic ring expansion test, where is a good place to start? Generally, what is a good procedure to follow when setting up an experiment? I am not very experienced but I would like to learn. The...

General relativity passes test at Milky Way’s central black hole by Ken Croswell For the first time, astronomers use stars orbiting a supermassive black hole to test Einstein's general theory of relativity, finding no sign of a fifth fundamental force. Links: John Batchelor Show...

Test for symmetry about the x-axis, y-axis and origin. | y | = 2x - 4 What are the rules for testing for symmetry?

Test for symmetry about the x-axis, y-axis and origin. y = | x | - 2 What are the rules for testing for symmetry?

I am a high school graduate from India ( GPA of 4.8 out of 5), and I am planning to go for a physics major.I got an admit at the University of Massachusetts Amherst with a good scholarship and all but I recently found that most of my friends in the States had already taken an AP exam which I...

I've got these tests They show the growth of a plant in mm and I have to test if the growth is superior to 1.1mm I think I have to get the p-value from KS test but I'm not seeing how

Hi, I'm performing tension tests using a dog-bone specimen conforming to ASTM E8 on 6061-T6 extruded aluminum alloy. ASTM E8 says the surface preparation should be as the product specified. The material I ordered is low grade bar stock 2" wide by 0.25" thick. If I am going to reduce the...

Hi, I wasn't too sure what forum to put this question in, so I apologize if it is in the wrong one. I have been looking at the past exams for the USA physics olympiad ( https://www.aapt.org/physicsteam/2016/exams.cfm ). I have been pretty good with the fnet=ma exams, but when it comes to the...

So, I'm sure many of you have seen the experiment recently by a flat-Earth member who brought a level on a plane with him in order to determine whether or not the Earth is flat or round. And yeah, my immediate thought was similarly "how silly!" But it did make me wonder: Could you do it that...

Is there a quick test to determine if a system of nonlinear equations is inconsistent. For example, suppose there is a system of equations such as: 3x cubed + 2y cubed = z cubed 2x cubed + 5y cubed = z cubed Since these two equations are clearly not dependent, could we say that since...

I know a real test of this unit would be to mount it and run, checking DC and AC voltage, current etc. The plan is to mount it on my Super Dexta, but this would need some work as there's currently a dynamo which is starting to fail. I was given the alternator free and would like to bench test it...

Homework Statement In the consolidated undrained , why there's only increase in pore water pressure due to deviator stress application ? Why in unconsolidated undrained test , why there is both increase in pore water pressure due to deviator stress application (ud) and also uc ? Homework...

Homework Statement This is the problem regarding with Consolidated drained triaxial test . I have uploaded some photos here . The first photo is from my notes . While the 2nd until the 3rd photo are from my refernce book . Homework EquationsThe Attempt at a Solution In the first photo , I don't...

Homework Statement A purified protein fraction containing buffer with salt can be desalted by one of the following techniques: (1) Gel filtration chromatography (3) Paper chromatography (2) Affinity chromatography (4) Thin layer chromatography2. The attempt at a solution Well, the analyte...

Homework Statement The article “Variance Reduction Techniques: Experimental Comparison and Analysis for Single Systems” (I.Sabuncuoglu,M. Fadiloglu, and S. Celik, IIE Transactions, 2008:538–551) describes a study of the effectiveness of the method of Latin Hypercube Sampling in reducing the...

Homework Statement [/B] A new concrete mix is being designed to provide adequate compressive strength for concrete blocks. The specification for a particular application calls for the blocks to have a mean compressive strength μ greater than 1350 kPa. A sample of 100 blocks is produced and...

Hello! I received a scaled score of 990 on my GRE and a percentile of 94. Can someone explain to me what the scaled score means and out of how much is it. Also how good is the score for applying to top rank universities (Caltech, MIT, Harvard) i.e. I want to take the math GRE too, even if I go...