Positive Definition and 964 Threads

Homework Statement Could anyone explain to me what exactly is positive and negative control in an experiment? Homework Equations The Attempt at a Solution

This is a very quick question but in the equation e=1-Q_{C}/Q_{H} do we treat both Q's as positive even though heat goes in in one case and out in the other? Or is there some detail I'm missing that would otherwise make the result less than 1.

I have a situation where I am using Newton's Method to solve a highly nonlinear, non-analytic equation with both positive and negative zeros. My situation requires that only positive zeros be found. Does anyone know any extensions to NM to restrict the solutions to greater than zero? Thanks.

Hi, Srednicki says in Ch20, we must remember that the mandelstam variable s is positive. However s is defined as s=-(k_1+k_2)^2=(E_1+E_2)^2-(\vec{k_1+k_2}).(\vec{k_1+k_2}) . Using metric (-+++). I can't quite see why this must be always positive? or why for that matter t and u are negative...

"Hydrogen Is Positive" Hello; My physics teacher said that hydrogen was positive. But, I don't understand why this is true. I thought hydrogen, like any other element, was electrically neutral (because it has 1 proton and 1 electron). So why is it positive? Thanks.

I'm just wondering, if an op-amp is connected in a positive feedback configuration, should the output not saturate immediately? Here is an example circuit i made in pspice along with its input/output curve (V12 has amp of 3v). http://img689.imageshack.us/img689/1286/posfeedback.png As...

Homework Statement Given a real symmetric matrix A, prove that: a) A is positive definite if and only if A = (B^T)B for some real invertible matrix B b) A is positive semidefinite if and only if there exists a (possibly singular) real matrix Q such that A = (Q^T)Q Homework Equations...

Why is the positive charge of the NAD+ molecule located on the nitrogen in the nicotinamide group? This nitrogen has 4 bonds attached to it, but nitrogen only has 3 holes in its valence shell, so wouldn't this make a negative charge on this nitrogen?

Homework Statement If a and b are positive real numbers, and \lambda^{2} = ab, then \lambda = \pm \sqrt{ab}. Homework Equations None. The Attempt at a Solution This is more of a conceptual question that has always escaped me. I do not understand how the square root of two...

One time me and a friend were having a debate over skill on certain activities. I said to him, "I'm not bad at basketball, but I'm not good at it either." He began to explain to me that the statement was illogical and that I "either had to be good or bad" Do you think its correct to assume that...

What is the difference between positive work and negative work? Because the definition of work is the dot product of the force and displacement vectors, I can see that work is negative when the force acts in the "opposite" direction of the displacement. Also, I see that W = -(delta)PE. I ask...

I am slightly confused as to why some circuits are drawn with a positive input terminal and a negative input terminal, whilst others are just drawn with a positive terminal and a ground (OV) terminal. What is the difference between ground and negative? Does negative indicate an excess of...

I am curious to know how g'Bg compares with g'g when B is a positive definite matrix and g is a vector. Is g'Bg >= g'g ? Thanks, Karthik

In a gas laser, an electron in the highest energy state absorbs photon for stimulated emission to occur, but now since it has more energy than its highest state, shouldn't it escape the atom and the active medium be left only with positive ions?

Hi I have an assignment due tomorrow, and have answered all the questions, I am just unsure about positive or negative flux I know 5b) is positive, I think 6 is positive, and I'm guessing the other two are positive, but can anyone confirm? And if I did get the sign wrong, would I have to...

Find the x component of the vector A? Find the magnitude of the vector A? Please also explain your work too thanks in advance

Sphere A corries a net positive charge, and sphere B is nuetral. They are placed near each other on an insulated table. Sphere B is briefly touched with a wire that is grounded. What would happen to the neutral sphere? I know it woul become a neg charged but i don't know what happens when its...

For an inverting op amp with the positive input grounded, the equation for V(out) is (Vin)*Rf/Rin. Thats fine But what if the positive input is not grounded? What if there is a voltage applied to that input as well? How would I find V(out) when the positive input voltage is larger than the...

Homework Statement Find the limit of the given sequence as n -> inf. ((n!)^2)/(2n)! Homework Equations We have been told that the squeeze theorem may be helpful. The Attempt at a Solution Using the squeeze theorem, I get stuck. I tried factoring some things out, and seem...

We can name many negative consequences from greed upon our global financial system. What, however, would you say is the most positive economic effect of altruism worldwide?

Hi, I was wondering about something in my notes that I don't quite understand. In positive beta decay in nuclear physics, we have a proton becoming a neutron and kicking out a positron and an electron neutrino (which is assumed massless here). In the expression for the energy released, Q =...

Hi, this is my first post.. It was something i was thinking about when laying in bed last night about to drift off. since spacetime is a "plane" where by mass directly effects the curvature, and in doing so, also effects our concept of time. Let's assume that the curvature of spacetime in a...

Homework Statement Prove that the integral from 0 to x of (sin t)/(t + 1) dt > 0. (Sorry I don't know how to use the integral latex.)Homework Equations We have only learned about lower and upper sums, and how the integral is equal to the supremum of lower sums and the infimum of upper sums when...

Homework Statement When writing Fnet=ma you are supposed to list the forces in Fnet -Ffriction + Weightparallel= ma how do you know when to put the negative or positve sign in front of the values? like on inclines and horizontal surfaces Homework Equations The Attempt at a Solution

Given positive interger N, now many non-decreasing sequences of length N are there whose entries are less than N?

Find all solutions in positive integers a; b; c to the equation a!b! = a! + b! + c! I have rearranged and got (a!-1)(b!-1) = c!+1 And the only solutions I can find are a=3 b=3 c=4 but I can't be sure that they are the only ones. How would I go about finding other solutions? I have...

I am with an aircraft squadron and we have a conditional inspection for aircraft that pull an excessive amount of "G's". The inspection is to check significant parts of the aircraft that might crack or buckle under certain amounts of stress. There is an arguemt in the shop about going from a...

I'm attempting to solve a multiple regression. My problem is that I want the resultant function to be always positive. I need a regression of the machining cutting force for several values of cutting parameters (cutting speed, depth of cut, ...). The cutting force has to be always positive...

Homework Statement Suppose a 6.00g bullet traveling at 100m/s strikes a bulletproof vest and comes to rest in about 600microseconds. What average force will it impart to the happy wearer? Homework Equations Use the Momentum-Impulse Theorem I took the initial direction of the bullet as...

just a question about the energies associted wuth the schrodinger equation> are the energy values always positive values. I thought that since when the eigenfunctions exist the particle is in a bound state, that the energy should be less than that required to escape a bound state and should be...

Homework Statement Find an operator T on F^2 such that <T(v),v> is greater than or equal to 0 for all v in F^2, but T is not self-adjoint Homework Equations The Attempt at a Solution I am trying to to find examples where <T(v),v>=0 where the operator is not 0

Proof: N2 > N rules out all the others. :-p

hello every body I know before happening fireligh negative charge is downer than the positive charge but my question is why it happends?

Homework Statement The handle of a hydraulic jack is 15 cm long and is pivoted 2.5 cm from the input piston which has a radius of 0.60 cm. The output piston has a radius of 1.2 cm. What weight could be lifted by the jack if the person pushing on the handle is to exert no more than 110 N of...

Homework Statement I don't know when the work of a spring is negative, and when it's positive... When is the work of a spring negative and when is it positive? Homework Equations Wsp= -(1/2)(k)(xf2-xi2) The Attempt at a Solution I can get Wsp to be positive when the spring is...

Homework Statement Consider a particle (which mass is m) and the following unidimensional potential: V(x)=\begin{cases}+\infty & x<0\\ -V_0 & 0<x<a\\0 & x>a \end{cases} Let E be positive. Find the spatial autofunction. Homework Equations I'm convinced that I have to use...

If C = A +B where A,B are both p.d, than C is p.d and its eigenvalues are positive. Waht can you say about the relationship between the eigenvalues of C, and A,B ? Thanks.

well this is the question... if a,m and n are positive integers with m<n, then (a^(2^m)+1) is a divisor of (a^(2^n)-1)... I started using induction and it works for the first step... but for the second one i do not know if i can make induction on m... any hint would help.. thanks :)

Just interested how this positive charge occurs. Thank you :smile:

Homework Statement http://img41.imageshack.us/i/photolu.jpg/ Homework Equations Right Hand Rule The Attempt at a Solution I have to find the moments at B. I know I have to use the right hand rule to figure out which force has a positive and which force has a negative action...

The positive powers of 2 mod 5^m cycle with period 4*5^(m-1), which you can prove by showing that 2 is a primitive root mod powers of 5. I want to prove that the positive powers of two, mod 10^m, also cycle with this same period. How do I go from this powers of 5 result to powers of 10...

Let P and Q be Hermitian positive definite matrices. We prove that x*Px < or eq. x*Qx, for all x in C^n (C : complex numbers) if and only if x*Q^-1 x < or eq. x*P^-1 x for all x in C^n. I guess I should use the definition of a hermitian positive definite matrix being x*Px > 0 , for all x in...

I was under the impression that energy had to be positive. Yet it seems we are still forced to use negative energies since we set the potential to be 0 at an infinite distance away. And the only reason we don't set the potential energy to zero at the origin of the source is because there is a...

Homework Statement My prof showed us the proof that sqrt2 is not a rational number. She said, however, that we haven't proved that it is irrational, because we haven't proved that sqrt2 exists. How would we go about proving this? Homework Equations N/A The Attempt at a Solution...

A cat rubs against a pair of rubber boots. What charge is found on both? Explain. Is all rubber non conductive or would I say the cat has a negative charge and the boots a positive charge? Thank you.

I'm studying for a test. In doing one of the old tests and it had a question that I couldn't do. Let T: Rn \rightarrow Rn be an operator on Rn, where n is an odd positive integer. How do I prove T has at least one eigenvector in Rn

Homework Statement A motion detector is placed on the top of a ramp sloping down. A cart is placed at the other end of the ramp (bottom of the ramp). The cart is pushed up the ramp towards the motion detector (top of ramp), and stopped at it's highest point. Homework Equations 1. Is the object...

In free-fall acceleration, how do I figure when "g" is positive or negative? Homework Statement My textbook is confusing me a bit. In general, when would "g" be positive and when would be negative? I thought it was when the particle was falling downward, it was positive and when it's going...

Homework Statement Imagine a positive point charge on the left side of the picture and an area defined by a loop on the right. I was asked to draw and label the area vector and sketch the electric field lines due to the point charge, which I did. The next questions asks: Is the electric...

how do i find at what negative time and positive time does the particle pass throught the origin?