Test Definition and 1000 Threads

Homework Statement So I just had a Physics test and I couldn't get the solution to this problem. I was hoping someone could tell me how to do it correctly. This isn't the exact wording, as I already forgot it, but here it goes: A skateboarder moves on his skateboard horizontally 3.2m, in...

Homework Statement Homework Equations The Attempt at a Solution I have no ideas how to continue. I also tried the comparison test but I don't know where to start. Please guide me...

The sister of my girlfriend gave birth to a baby suffering Lowe syndrom. The baby who is now a child of 5 years old had been diagnosticed by his symptoms (cataracts at birth, problems with his kidneys, mental problems+convulsions and more medical tests that I'm not aware of). Just to give you...

http://www.parade.com/askmarilyn/2011/12/Sundays-Column-12-25-11.html Would someone please explain this to me? It goes against my intuition as well. ---------- Post added at 11:19 PM ---------- Previous post was at 11:05 PM ---------- I think the answer should be 1-P(chosen no...

Fun Problems! Evaluate the following: 1. \( \displaystyle \sum_{n=1}^{\infty}\frac{\left( 1+\dfrac{1}{1!}+\dfrac{1}{2!}+\cdots +\dfrac{1}{(n-1)!} \right)}{2^{n-1}}\) 2. \( \displaystyle \sum_{n=1}^{\infty}\frac{1+2+2^2+\cdots+2^{n-1}}{n!}\) 3. \( \displaystyle...

I read here http://www.eoht.info/page/Genius that henri poincare got a 35 on an iq test. I think that is really interesting, if its true! I've heard that people with mental deficiency score in the 60's, so 35 would be really low! I used to think iq meant something years ago, but I dropped...

Has anyone used a home DNA testing service? I was looking at 23andme service. The reviews are pretty good and it's only $100. Could be interesting. What do you experts think? Worthwhile?

Hi everyone! Lately I have been trying to improve my typing speed, and have been playing a game called Type Race, where you type various short passages (the passages are selected at random from a text bank) and your score in WPM is recorded. What I want to do is determine whether or not my...

Dear All, I have two functions that are defined on a table, i.e. f1(x,y), f2(x,y), where x and y are bin indices, and 1\leq f1(x,y) \leq 1 , 1\leq f2(x,y) \leq 1 . I would like to perform some test to show whether f1(x,y) and f2(x,y) are significantly different. Is there some way to do...

Test Tube Yeast Evolve Multicellularity The evolution of multicellular organisms have always been poorly understoond. Recently, scientists managed to demonstrate the evolution of multicellularity in yeast cells through artificial selection.

This is my first post. The sticky on Latex is very useful. Looks like I will be learning the code for formulas. Would like to know if you can test the code without posting to the board - how to play with the code and view results locally first. I am also trying to attach an image. Darn -...

Homework Statement Had a test today and had to do these problems. I just want confirmation on whether or not I did it correctly. (One) A sledder is at the top of a (frictionless) hill. He has an initial velocity of 5m/s, and his weight with the sled is 30 Kg. B) What his his velocity...

Help me! I am looking for a test method that will allow me to sample process air and measure the sodium content resulting from reactions with sodium hydroxide. This will be in the ppb range. Any suggestions or possible methods would be helpful.

Flame tests are used to test the color that a metal produces when heated and the electrons release energy when falling back to the ground state. This i understand, but why does the procedure only test the metal part of the salt? In other words, why does the anion part of the ionic compound not...

Hello, I have 2 questions: First, where can I find the best graduate schools for PDE & Probability? I'm thinking MIT and NYU are really good, although I could be wrong. Second, I was wondering if my expected math background is good enough to get into the 90th percentile on the GRE...

hi i have a physics questions about sound Sound waves are used to detect faults in girders. a cro is used to detect these faults, a pulse producer and a detector is placed on opposite sides of the detector. The safe detector has a upwards spike at 0microseconds and at 10 microseconds. The...

i'm currently taking grade 12 physics. my teacher is really nice, but i got say that she sucks at teaching, and the textbook we're using is worse. can anyone here help me with understanding the basics theories and equations I need for this test?

I'm trying to run a hypothesis test to see if a data set follows a normal distribution. I don't want to look at a plot. Is there any way? I tried to build a program that uses the built-in normal distribution functions to calculate how far the points on a normality plot would fall from forming...

Homework Statement a) Test the following series for convergence using the comparison test : sin(1/n) Explain your conclusion. Homework Equations The Attempt at a Solution i must show f(x)<g(x) in order for it to converge other wise divergence. g(x) = 1/n sin(1/n) >...

Hello, I want to test gearboxes. How do you recommend I test the continuous torque of a gearbox and also the peak torque of the gearbox? I want to test to see the maximum torque the gearbox can handle. How do you suggest I go about doing so? What type of equipments or measuring devices...

I had this doubt studing GR, but let's consider SR for semplicity, where g_{\mu\nu}=\eta_{\mu\nu}the geodesics are 0=ds^2=dt^2-dr^2 we obtain the constraint we obtain the constraint r=(+/-)t So it is a well known light cone, but in SR we have that a (test?)particle can always move in a...

Can someone give me some two dimensional and projectile motion questions in this thread to work on? I've got a test coming up, and I'm still not 100% with the topics. If you can help-please do so! We all know how it feels to be stressed, cmon people! :smile:

Hey, could anyone explain how you would preform a sinusoidal test on large vehicle (weight>40 tons). I have a graph from sinusoidal data, but i don't understant how they were able to obtain this information because there is not a powerful enough testing device.

Anybody know of some simple tests that are used on valves for flow and pressure drop experiments? is there anythign published online that ye could send me a link to if possible?? thanks in advance regards dave

What kind of job in the science or engineering field would have you build stuff and do experiments. I talked to a guy that worked as an engineer, and he said they had to do a lot of paper work to do anything and he said it wasn't fun. And another guy I talked too said at nuclear power plants...

Homework Statement http://bhs-jones-physics.wikispaces.com/file/view/torque+wkst.pdf questions 2 3 4 5 please!

Hi there, just wanted to make a clarification before my final exam. The second derivative test for partial derivatives (or at least part of it) states if D = ∂2f/∂x2 * ∂2f/∂y2 - (∂2f/∂x∂y)2 and (a,b) is a critical point of f, then a) if D(a,b) > 0 and ∂2f/∂x2 < 0, then there is a local...

Hello Everyone, To put it shortly: I am a 15year old Sophomore in HS who would like to leave & test out of high school (GED), study at community college, and head to a state school (NC State or UNC), or Caltech (if I can find genie). Where I plan to Major in Physics and Philosophy I've...

Well I'm a really great physics student, but our teacher told us that no one will get a perfect score on the exam we're going to be taking on wednesday, but I believe that i can do it. Do you guys have any good test taking procedures that you do before a test?

Mod note: Link removed by request of the particular website It takes about 20-30 minutes to finish. My results: Leading and Deciding: 5 Supporting and Cooperating: 2 Interacting and Presenting: 2 Analysing and Interpreting: 2 Creating and Conceptualising: 3...

Hi, I would like to confirm that I have understood this correctly. The steps to find local maxima/minima of a function f(x1, ... , xn) are: 1) We find all the stationary points. 2) We form the Hessian matrix and calculate the determinants D1, D2... Dn for a stationary point P we want to check...

Hi every body I've some question that need to be answered WHy DC high voltage test devices always generate negative voltage rather than positive voltage I hope that i can get an answer Thanks

Alternating series test: 1. All the u_n are all positive 2. u_n\geq u_{n+1} for all n \geq N. For some integer N 3. u_n \rightarrow 0 I thought it would hold with 2. and that the su m of the N first terms were not \infty Here is the theroem just in case...

Problem: I have a sensor monitoring a process which is controlled by a feedback controller. This sensor fails from time-to-time and I need to replace it with a new one. I have always used the same type of sensor, say type A. Some sensor manufacturers are offering me an alternative sensor...

Homework Statement The Attempt at a Solution I got that the limit goes to infinity using the Ratio Test and that would mean B. But I'm not 100% percent sure. Just looking for some to verify my answer if I'm correct or not.

Hi. I have a test on friday, and I was given a sheet to review. However, many of these questions I have no clue how to answer, as my teacher never went over them. I'd really appreciate a step by step walkthrough on how to do the problems, as I don't want the answers, I want to know how to...

Everything about the subring test is straightforward from the subgroup test, but the multiplicative operation of the subring, S, of ring, R, needs to be closed wrt multiplication, *. How do you prove S is closed wrt * if the only assumption about * is associativity and distributivity over...

I just got out of my modern physics final exam and am pretty positive I completely bombed it. This will at least give me a C, or even worse a D in the course. Of course I don't know what I got on the exam, but I know it wasn't passing. I am very disappointed in myself at the moment, but I...

Homework Statement Ʃ((x-3)^(n)) / (n*2^(n)) Homework Equations lim as n→ ∞ (An+1 / An) The Attempt at a Solution When dividing two fractions, invert the second and multiple to get what you see below. (x-3)^(n+1)/((n+1)*2^(n+1)) * (n*2^(n))/((x-3)^(n)) Do some cross...

I am doing a wind tunnel experiment on aerofoil. So i need some idea to mount my aerofoil in the test section. The aerofoil is made of acrylic. So which type of stick will suitable for my aerofoil mounting. The configuration as shown in picture that attached. (Picture taken from google image).

Hello every body .. What Is Heat Run Test??

Java [String a = new "test"] vs [String b = "test"] Can you tell me what is the difference between the two? What is going on behind the scenes?

Hey everyone, I recently got a job tutoring a High School student in physics. I'm in fourth year at university. I've just had my first session, and I quite enjoyed it. Though I'm now very nervous about my student's upcoming test. I'd like to give some interesting physics related...

Hi, I am preparing for an entrance test for a grad program but I have not taken physics past gr.11. I am wondering how realistic is it for me to learn the below concepts relating to more biophysics in 3 months? is there any books to recommend? - kinetics, kinematics, force, Newton's laws...

I don't know where to ask this question, but anyways, since it was asked in an exam, so finding out the correct answer afterwards is a moral responsibility as a homework. So here I am. My question is whether the compound 2-Hydroxy-5-nitrobenzaldehyde (Did I named correctly?) gives positive...

How to study for toefl test?? My first language it is not English and I am thinking on applying for US or British schools of physics in order to study a Master. I have, let's say, an advanced level, but I think that I have to work a little more with my English(This would be to improve my...

Use a comparison test to determine whether the series \sum (n+1)/(n^{2}+n+1) diverges or converges. I started out by simplifying the series to 1/n+1 and then from there I compared it to 1/n, which converges. 1/n is greater than 1/n+1 so based on the comparison test, the original series...

Vickers Hardness Test Question : For Vickers Hardness Test to test the material hardness we uses different force [kfg], Why do we need to use different force like 1kgf and 5kgf? Brinell Hardness Test Question : Pure Copper : Require force is 62.5 Steel : Require force is...

What test or distribution should I use for before and after treatment? Say, I have 30 subjects I test their blood before and after a pill they take a pill, what kind of test should I use? I want to test mean difference, so, paired t-test? or Wilcoxon signed rank test? The data looks like this...

Homework Statement I'm this series to see if it's convergent or divergent. I tried the root test, but it came out inclusive, and now I am trying to figure out if the ration test works. The only thing I'm asking which would be the right test for this. Homework Equations ∞Ʃn=1...