Testing Definition and 634 Threads

I am designing my own Charpy impact testing machine and I am unsure what would be the best as well as relatively simple and affordable method I can use to accurately measure the angle the pendulum travels after it has broke the sample. I would also appreciate any complex and more expensive ideas...

A livestream video feed from the event has started and can be accessed via the CS homepage [1] or the corresponding blog on Wired [2]. Some background information about CS can be found on [3] together with a (very) short description on the TM65 [4]. [1] http://www.copenhagensuborbitals.com/ [2]...

Homework Statement Test the series for convergence or divergence\sum_{n=1}^{\infty} \frac{n!}{4.7.10...(3n+1)}x^n,\; x>0 The attempt at a solution I've decided to use the ratio test because of the factorial. L=\lim_{n\to \infty}\frac{u_{n+1}}{u_n} I worked it out and i got: L=\lim_{n\to...

i'm doing a task to find the amount of sodium hydroxide (NaOH) in a liquid soap. i have to use titration in it. how exactly would I do this? thanks

Hello, I am using a hydraulic shop press, to test the strength of acrylic weld joints. Here are my questions. -I replaced the pressure gauge that was included with a very precise digital gauge. The hydraulic piston that presses down has a removable circular head 2” DIA. Its neck is 1.48”...

Hi folks. Just looking for some input please. I have a dataset containing interval data (one dependent and 6 independent variables) and taken a random 90% sample (approx 300 observations). I've performed a linear stepwise regression on the 90%, in order to obtain a model to predict the...

In a parallel thread the scientific method became a subtopic, together with claims concerning "Intelligent Design"; a little elaboration may be useful. A discussion of the "scientific method" can be found in Wikipedia (I think that the summary is quite OK); a clear description can also be found...

Why does necking occur during tensile testing of ductile materials?

Literally running out the door, but came upon this. It seems to be a really interesting avenue to test GR vs. other gravity theories using hoped for GW detectors. http://arxiv.org/abs/1204.2585

Hello all, I'm in my final year of engineering so I'm required to complete a thesis as part of that. My topic is to investigate the wind loading on a typical conveyor belt + truss arrangement, because there's a lot of uncertainty in industry about drag coefficients etc. I've attached a model...

Hi, I am building a device. I need an in vivo procedure to perform the experiment. The experiment is based on shinning the red led light on to something just say finger. But I can't test it on any people or animals as of now. I need measure the measure drug concentration. So I need some kinda...

Alright. I know how incredibly inefficient this algorithm is, but I felt like giving this a whirl. #include <iostream> #include <cmath> using namespace std; bool prime(int x) { bool j = true; for (double i = 2;i == x;i++) { if (x/i == floor(x/i)) { j = false; } } return j; }...

I have a question about the equations used for hypothesis testing. They all look like this one here: H0: μ = μ0 H1: μ > μ0 For various situations.. sigma know, sigma unknown etc. So H0 is the first claim and H1 is the second claim. But this means the second claim is > than the first...

I'm currently taking a Microprocessor course and we are adding to our breadboard week by week. The most recent add on was a UT6264CPCL RAM chip. Other chip specifications are given below in in 2. Homework Equations . My question is, how do we test to make sure that the RAM is working using two...

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?

I have created a program in MATLAB that creates a b-spline surface from a set of (x,y,z) points. I would like to see if my program works before I develop it into a full program (user interface plus lots of options). Here's what I'm asking... Could someone generate a b-spline surface of degree...

1. Consider a correlation function between two points `A(x1,t1)` and `B(x2,t2)`, we need to integrate over paths which could be infinite long. But the time length `(t1-t2)` is finite, so if A and B are the coordinates of one single particle, then all of the paths from A to B should be time-like...

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...

I need to drag a ring across a surface by pulling it with a string attached to a motor. The motor will simply coil the string, or the motor will be attached to a pulley and the ring will be tied on the rope. My key problem: the surface is not conventional so there is no friction coefficient...

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...

I work for a company that manufactures and sells night vision scopes, day time optics, lasers, and pretty much anything that mounts to a weapon. I wanted to test our equipment to see how well it holds up to various recoil of different weapons but ammunition is very expensive and it is very...

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...

Hello folks. This was in my exam and I wasn't sure how to solve it. Homework Statement A sample of 67 respondents was taken collectively by a population of 6,456 units. The number of those who said they were available to implement a development program were 35. To implement the program...

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...