Elementary Definition and 537 Threads

Hello, the following integral confused me a little bit: \int_{0}^{\infty} e ^ {-2.x^2} dx The answer is \sqrt \frac{\pi}{8} and I have no idea where this answer came from. Do I start by saying let u = e^ {2x^2} ?

Hello everyone, I've been searching in this book forever to find an example but no luck. My problem states: Find two Elementary matrices E1 and E2 such that B = E_2E_1A A = 2 3 -1 8 B = 1 11 3 -24 Can someone explain to me what they want me to do? The books says: A -> E1A->E2E1A -> Ek ...

This problem I have to do is really bothering me. Your 1600 kg PT Cruiser moves around a level 50m radius road. The coefficient of STATIC friction between the car tires and the road is 0.80. Determine the MAX speed of the car so that it does not skid off the road. I think I get somewhere...

Hi, I'm having trouble with some questions. I did elementary linear algebra a few months ago but seeing as I've forgotten most of it I'm effectively new to this. Anyway can someone help find a basis for Im(T) the following transformation? T:R^4 \to R^3 ,T\left( x \right) = Ax where A =...

How many elementary particles have been discovered.

Not sure if this is the correct place to post (not homework because I am studying maths and mechanics in my own time...not a general maths problem either) but... I have been working on a problem for a while now that has not only kept me up into the early hours of the morning, but has also...

I am working with the following equation: |1 -2 3| |6 -11 15| |4 -14 21| a. add -4 time Row1 to Row 3 b. add -6 times Row 1 to Row 2 c. add 6 times Row 2 to Row 3 d. multiply row 3 by -1/9 I have come up with the following answer: |24 -48 72| |180...

I know this probably should be in the K-12, but I'm in college and I am enrolled in a general physics course. Okay, my question is if a rock drops off a sea cliff (note: NOT THROWN), and the sound of it when it hits the ocean water is heard 3.4 s later. And the speed of sound is 340 m/s. How...

I can't seem to apply what I've learned in EE to the most elementary problems. I have two questions. The first is based on an observation. When we plug in our blow dryer, and turn it on, the lights dim noticeably. Why? My attempt to think about it involved connecting another load in...

Well my chemistry lecturers have always explained to me (in introductory chemistry) that most chemical reactions occur due to the components desiring to acquire a more stable state. My high school physics teacher explained to me that when you put metal in fire it heats up and later releases...

I plan to take the course elementary differential equations during the summer period, however I have experience up till integral calculus, which I just completed. Would anyone here advise another class should be taken before differential equations (such as multivariable calculus) or that it is...

Calculating charge and force of electric repulsion Calculate the force of electric repulsion between two small spheres placed 1m apart if each has a deficit of 1x10^8 electrons. I tried this and only got r=1m and N=1x10^8 I don't know the equation needed for this please help.. Thomas

Could someone help me please? 1.) Find the scalar equation of the line containing P(2, -1, 3) and perpendicular to the lines [x y z]^T=[4 -1 2]^T + t[7 0 1] and [x y z]^T=[-2 0 1] + t[2 3 0]^T. 2.)Find all points C on the line through A(1, -1, 2) and B(2, 0, 1) such that vectors llACll= 2...

Can anyone here explain this theory to me? I'm told that it agrees with all experimental data, yet also manages to disprove (or at least interpret differently, I'm not really clear on this) the Heisenberg Uncertainty principle. If anyone can explain this theory to me, I'd be grateful.

Let W be a sample space with a countable number of outcomes. Let A be the set of elementary events (an elementary event is a set containing only one outcome from the sample space). Prove that the sigma-algebra generated by A is the set of all subsets. Any advice?

'Silicon and phosphorus are both covalent substances, but silicon has a much higher melting temperature than phosphorus' Explain this statement. That was the question..im a bit stuck on it. I don't usually ask here, but I am out of ideas for this for now.. I first thought of the...

Although I have completed two semesters of basic physics, I'm going to need to take a calculus based physics course this spring. I am a bit concerned since it's been a while since I took calculus; does the course utilize calculus extensively (in terms of the amount of theorems one will have to...

\int x^n \cdot \sqrt{1-x^n} \ dx It seems as the only time this is an elementary function for n > 0 is n=1 and n=2, can you prove / disprove this? n is an integer

Hi, I am looking for some math projects or ideas to my students in the elementary level: Grades 4 and 5. they're using the harcourt textbook. But i want some nice, new and maybe weird ideas such that they can do it with me or by their own. I need to put these math projects in the school's...

Hello Cyclopentane is dichlorinated and I have to write down the structures of all the dichlorinated cyclopentanes formed. I took monochlorocyclopentane and monochlorinated it. The point is that I get confused with the stereochemistry here since the answer is different from the one I have...

I am currently reviewing for an upcoming test over sets. What the instructor did was to give out the test he gave out for last semester for us to study from. I can answer most of these questions but there are a few that I am a little bit unsure of. Some of the questions are complete the...

Let C be a circle and let D be the set of all diameters of C. What is \capD? I think it is the center of the circle since that would be the only point of intersection of all the diameters of the circle. Could someone let me know if I am correct? Regards Jeremy

Hi there. I'm currently writing an essay on the four fundamental forces of physics for my Advanced Higher course (an SQA qualification) but I got confused on a couple of issues: 1. what quarks make up protons and neutrons? 2. what's a gluon? 3. do neutrinos do anything at all except fly...

A Pie zero meson ( rest-mass energy 135 Mev) is moving with velocity .8c K in the laboratory rest frame when it decays into 2 photons, gamma1 and gamma2. In the pie zero rest frame, gamma1 is emitted forward and gamma2 is emitted backward relative to the pie zero direction of flight. The...

String and Tension When reading about string theory, the introductory notion seems to be that the tension in a string is what accounts for its properties, allocating it its mass, charge...However, what is it that causes the actual tension in the string? It is said that the graviton represents...

Hi everyone... I have answered already a lot of questions here on the topic of the different elementary particles in the Standard Model. For this reason I will give the interested reader this site that describes this subject very clearly...

Electrolysis will release the elementary components of a medium, albeit the process required a fare amount of energy, is there any other reasons it would be considered secondary to a more effience process? Does it have any pros?

Using only three 9's along with elementary math symbols like + or -, see if you can arrange them to represent the number 20. Remeber that 99/9=11.

OK, I am relatively new to Chemistry, but our school is having a science fair competition soon, and my Chemistry teacher wants us all to do something. Since we are not seasoned warriors of practical Chemistry yet, we are not planning on making bombs, or anything as dangerous and complicated as...

Hi all, I'm trying to understand something about the lagrangian. My resources for learning a currently limited to Landau's mechanics and anything which is on the internet. L = L(q,\dot{q},t) Now, here is a simple question: what are these generalized co-ordinated exactly? For...

Need some pointers handling this question: "Invent a subatomic particle and describe its likely properties. Where in the atom would you expect your particle to exist, would it be stable, what is its mass, what is its charge, etc.? Present your findings to the class via whatever media you wish."

Elementary Charge- NEED HELP! Object 1, a conductor with a positive charge og 0.02 C is brought into contact with an identical neutral object 2. How many electrons move from one object to the other and in which direction?

January 2004 issue of Scientific American contains a good elementary description of LQG. One point he makes in favor of LQG in contrast to string theory is that LQG does not require a background of contiuous space-time, while string theory does. Comments?

I need to design a lab that would determine the elementary charge(charge of an electron). We can not use Millikan's oil drop idea, we have to come up with our own and it has to work. I was thinking of maybe incorporating the photo electric effect but I'm unsure of how to do it.:smile:

I understand why two of the three row operations do not change the solution set of a system: 1. Interchange two rows. (Doesn't make much difference in what order one decides to write down the linear equations does it?) 2. Multiply a row by a scalar. (This step doesn't change the solution...

Hi everyone, I'm doing a course which contains foundation work on convergence. I was suprised to see the book I am using uses phrases such as... " This sequence clearly doesn`t converge " for sequences such as 2,0,2,0,2,0,2,0... I was expecting it to say something like " By theorem 4.5...

The question, broadly, is how many elementary particles do you expect to be in the final theory. But just to be more concrete, I have narrowed it to "fermions" as Pauli principle is the closest thing we have to ancient "impenetrability", fitting the naive idea of particle.