Testing Definition and 589 Threads

Hi there, I work in heavy machinery rebuilding and we were reviewing a leak test procedure to make it standardized. Essentially, the brake piston squeezes together the clutch plates (stationary) and the friction disks (which move with the shaft). The piston is pushed by compressed springs...

Homework Statement Use integration, the direct comparison test, or the limit comparison test to test the integrals for convergence. If more than one method applies, use whatever method you prefer. Homework Equations ∫sinθdθ/√π-) The Attempt at a Solution I don't know which method...

Do tensile testing machines reduce the value of load in these regions? If yes, why? If no, what's happening in the graph?

Hi I am testing that data are normally distributed by using chi-square test. I get a very high chi coefficient about 173. This is very strange because data fits at 3sigma test and median mode are equal so I am almost sure that is normal distribution. What I am doing wrong? Which test do you...

Hi. I'm testing a PMT and I'm surprised by the following. With power supply (-900v on K) and with no charge between output electrode and ground, I measure -126 V same with scope (Zin = 1 M) or DVM (Zin = 10 M). I must precise that this experiment has be made in a room not completely dark. Can...

\[\int_0^{\infty}e^{-x^2}\,dx=\frac{\sqrt{\pi}}{2}\] This is inline: \(\frac{\sqrt{b^2-4ac}}{2a}\) Other centered equation $$\Gamma(x)=\int_0^{\infty}e^{-t}t^{x-1}\,dt $$

hey guys. Something's been bothering me.. Well two things.. First of all, when looking at an algebraic equation and testing to see if its a function, why can X be squared, but not Y? our professor and book, gives the impression that something like: x^2 +y =1 is a function while...

Hi everyone. So I'm afraid I don't really know much about statistics, but I am trying to learn by working through a book, and taking some examples (I have mathematics experience, but from a biological perspective). Just now, I am looking at the hypergeometric probability...

Hi Guys, Could you please help me on the derrivation of offset and amplitude formula being used in the computation of ADC INL and DNL using code density testing. below are the formulas. Appreciate any help. Regards.

Hardhats are tested by dropping a 3.63 kg steel ball (free fall) from a height of 1.52 m and allowing it to impact the top of the hardhat. Hardhats are impacted with an impact velocity of 5.5 mps. The hardhats are supported at four locations where they are connected to a circular band that...

How do you see if the following inequality holds true for (-2,0)? (-x/4)*(x+2)>1 For that matter how do you test inequalities for a given interval in general? Certainly there must be a way other than to check all values of (-x/4)*(x+2) in (-2,0) and see if they are greater than 1?

1. I'm doing an experiment where I have a brass hollow cylinder, and I roll it down an inclined plane, and after each trial, I add fish weights to the inside of it to increase the mass. I'm testing the proportionality between mass and angular velocity, with my hypothesis being an inverse...

Question: Why is it not sensible to calculate the Young's modulus of the material (steel) when the experiments was conducted? But I thought it should be possible to calculate the Young's modulus after plotting the stress/strain curve. Young's modulus can be found by finding the gradient of...

I wanted to understand something about Inertial frames especially as they are talked about in SR. It appears that the laws of physics should hold the same in them. Now I understand that inertial frames only involve things moving relative to each other and moving in constant speed so you can...

So I have a structure that I have to test, or more so a "model" structure. It is in the shape of a T, but rotated on its side, so that the stem of the T is a cantilever beam. An actuator will be used to load the structure at the free tip of the stem. My task is to design the supports of the...

String Theory is basically the idea involving an indefinite amount of invisible "strings" vibrating at a large spectrum of frequencies, thus creating sub-atomic particles that compose everything we experience and ourselves. It would make sense if you could test this theory by creating something...

I need to simulate the flow of a river, to do small scale hydrodynamics testing on a partially submerged water wheel / paddle wheel design. The typical water tunnel setup will not work, because we are interested in the flow near the surface. The water wheel is half in the water, and half out...

Hi all, This is not really a homework problem, more of a 'what-if' scenario but I'm not sure which section to put it in. For a science project we have been asked to look at material properites and come up with a project (which will have a presentation :eek: but that's another story). I'm looking...

Is there any way to test things to see if those things are made of PVC? It's toxic, but if you have things that you are unsure as to what kind of plastic they are made of you would want to know if they are made of PVC. By the way, if you have flip flop shoes, throw them out because almost 100%...

For electronic devices that are made in large quantities, it's nearly impossible to test all the devices. How many samples do we have to test to get good confidence on the entire lot. Also, how do you select the samples for test - just pick them in random?

I tested creep in the labs at univeristy, one thing i am confused about is, we made a graph of the extension against time. Taking the gradient gives us E or secondary creep rate. Homework Statement The equation for this (without using gradient ) is, E= A stress^n e^-Qc/RT A and n are...

Hi i have to show that the series 1+2r+r2+2r3+r4+2r5+... converges for r=\frac{2}{3} and diverges for r=\frac{4}{3} using the nth root test. The sequence \sqrt[n]{a_{n}}comes a bit complicated so i was wondering if I can remove the 1st term a1=1 and show that 2r+r2+2r3+r4+2r5+... converges...

I've been working on a Special Relativity simulation/game, and I'm interested in getting some feedback. Basically, it is a flash game that incorporates time dilation, length contraction, and so on. I'm hoping that it will be a fun way to make these abstract (and confusing) ideas hands-on...

Should schools and organizations start drug testing students to monitor abuse of drugs like adderall, which is widely used recreationally by lots of kids to boost test scores?

[PLAIN]http://www.tempneff.com/jailtime/differential%20equations/HDE.PNG I learned how to solve homogeneous DE's from youtube videos. This presented a problem when during my last test, a question stated that i should show a DE to be homogeneous. The way I learned was different then the rest...

Hi, I am building control panel for automation testing unit. - Ambient Temperature to measure:- - pulley speed and temperature to measure. So far... for Ambient Temp I have used T-Type and for pulley speed I have used magnetic pick up 10V. And for interfacing used USB6009. Can...

I have looked everywhere to find a simple, easy test to find whether a wave is longitudinal or transverse, I've read my textbook and I think it may be to do with polarisation but I am not quite sure how, or someone said that passing the wave through a vacuum would determine the type of wave. any...

I tried using site, https://www.physicsforums.com/mathjax/test/preview.html but after putting in the codes and pressing enter, nothing happens. I will test by trying the code tags here: \frac{x^2}{a^2}+\frac{y^2}{b^2}=1 \frac{x^2}{a^2}+\frac{y^2}{b^2}=1 For reference, I used...

Is the only way to tell that I have a B field, is to take a test charge and place it stationary and see that it doesn't move? And then fire a test charge and see that it gets deflected when it is moving at a speed. And if my test charge moved from rest I would know there is an E field. Is...

Hi everyone, I am currently doing some experimentation with electromagnetic coils, I realize I will need a waveform amplifier for the testing using my rsr32 function generator. Could someone point me in the direction of a decently priced one?

Hi, I've just completed a prac, where a beam was placed into a solenoid with a current flowing through it, causing a force to exerted down and I balanced out the force by placing weights on the other end in the effort of calculating the magnetic field strength. Anyway, one of the short answer...

I can't for the life of me understand this topic. given a point x =(1,1,1,1,1,1,1) and a primal LP, does the point solve the primal? An internet search revealed no answer to my question, only criteria which involves knowing y. I am aware that \sumaijxj < b then yi = 0, so I at least know...

Ok someone tell me the official explanation of why alpha cannot be zero in hypothesis testing.

I have 4 problems left and the questions says I have to test them for converge or divergence. Here are the problems http://gyazo.com/f0fa5a38c5968ecb7e74103486a181bd.png http://gyazo.com/4689f9d02d0b264c2c2b64ff4907ba77.png for 25, I want to take the limit as n goes to infinity however I get...

Hello, I am trying to figure out what test to use in order to solve a fairly basic concept. I am not sure if this is a cenvergence test or a significance test. Example: Consider the following data x y 1 30 2 22 3 18 4 12 5 10 6 9 7 8 8 6 9 5.5 10 5.8 I want to...

Homework Statement Two system are given as follows :- (a) \frac{dy}{dt} + sin(t)y(t) = \frac{df}{dt} + 2f(t) (b) \frac{dy}{dt} + 2y(t) = f(t)*\frac{df}{dt} Test linearity of systems. Homework Equations The Attempt at a Solution

Hello All My company has several products that use an IR emitter & receiver in line and are used as a sensor to detect when something 'breaks the beam'. The problem we are running into is that several of these components are aging prematurely, but they work perfectly at the time of our...

I've done plenty of imaging performance testing on a variety of systems, from millimeter wave through UV. Until very recently, such testing required expensive and specialized equipment. Now, with digital imaging (at least in the visible), you can perform the same type of characterization on your...

I posted earlier about testing a project to simulate a wood 2x4 traveling at 67 mph, I did not really get the answers I was looking for so I am going to try to rephase it. My project needs to withstand the impact of a 15lb wood 2x4 traveling at 67 mph. I want to simulate this test but in a...

I want to see if the matrix w = (1,0;0,1) is a linear combination of the matrices v1 = (1,2;-2,1) and v2 = (3,2;-1,1) where ; denotes a new line in the matrix. I know for example if w and v were 1xn matrices i.e vectors such as w = [1,1,1] v1= [2,-1,3] v2=[1,1,2] then i setup a matrix with...

I have enabled MathJax on the site. There are no Latex images being displayed. Please post any problems. I'll leave it enabled for the next hour or so and switch back to images until we are 100% ready.

I think I did this right... \sum_{i=1}^{\infty} \frac{n}{e^{n^2}} I tried it with the root test to no avail. So I then tried it with the Ratio Test and I come to this expression... \lim_{n \to \infty} \frac{(n+1)}{e^{2n} e(n)} ...which is an indeterminate form (infinity over infinity)...

There was a problem that was talked about in class where we had the amount of quantity sold in one column and the promotion level in another column. The promotion took values between 0 and 0.88 with a number of values being zero. The problem discussed was to test the following hypothesis The...

Homework Statement Hi, So i don't know if this is a stupid question but i'll ask anyways. So I'm on the chapter where we start testing integrals for convergence. The books starts out with elementary functions then they move towards non elementary functions. Testing for them is OK, my problem...

Homework Statement Magic squares. An n × n matrix that is filled with the numbers 1, 2, 3, ..., n2 is a magic square if the sum of the elements in each row, in each column, and in the two diagonals is the same value. Write a program that reads in n2 values from the keyboard and tests...

Homework Statement Discuss the convergence of Integral(x3/2 sin 2x dx) range is from 0 to 1Homework Equations|sin x| =< 1 The Attempt at a Solution The sine function converges absolutely. It is also increasing from 0 to 90 degrees, decreases until 27 decrease and it is negative from 180 to...

I'm trying to design an impact testing rig and i need to use the currently existing chemical explosion rig as one of the solutions alrady existing in my report. But i can't seem to find very much on this, any help would be greatly appreciated. thank you

Hello all - I'm new to the forum - I hope some kind person can help with a question of calculating scale weight in a scale model of a glider. I want to test the glide ratio of a glider design by making a 1:4 scale model and thowing it from a certain height at a certain speed and measuring...

I am not sure whether this falls in this section or the other. But as the calculation of likelihood usually involves calculus, posting it here. Homework Statement The Big Boss at Amazoogle.com says that based on long experience, the best model for errors in software is that experienced...

I have a long C++ program that has a few simple statements in it. At the beginning I have ; #define NUM_DP 10 Further on in the program I have this conditional statement; short int ct, j; . . . ct = op2.test(op2.num); if (ct < (NUM_DP - 1)) for (j = 1; j < 20...