In mathematics, the concept of sign originates from the property that every real number is either positive, negative or zero. Depending on local conventions, zero is either considered as being neither a positive number, nor a negative number (having no sign or a specific sign of its own), or as belonging to both negative and positive numbers (having both signs). Whenever not specifically mentioned, this article adheres to the first convention.
In some contexts, it makes sense to consider a signed zero (such as floating-point representations of real numbers within computers). In mathematics and physics, the phrase "change of sign" is associated with the generation of the additive inverse (negation, or multiplication by −1) of any object that allows for this construction, and is not restricted to real numbers. It applies among other objects to vectors, matrices, and complex numbers, which are not prescribed to be only either positive, negative, or zero. The word "sign" is also often used to indicate other binary aspects of mathematical objects that resemble positivity and negativity, such as odd and even (sign of a permutation), sense of orientation or rotation (cw/ccw), one sided limits, and other concepts described in § Other meanings below.
I have in the past been criricised for inappropriate postings that I could have resolved with research so this time I have done the research first.
The best solution I have found is from wiki "that causes it to experience a force when placed in an electromagnetic field."
What causes the force...
Homework Statement
The question askes about the path of the electron. I need to know if I am doing it correctly whether it was asked for a proton or an electron.
Homework Equations
F=QV⊥Bsinθ
The Attempt at a Solution
I answered it C. Because it is an electron, I used my left hand. My thumb...
I continue to be occupied with the first chapter of Lessons on Particle Physics by Luis Anchordoqui and Francis Halzen. The link is https://arxiv.org/PS_cache/arxiv/pdf/0906/0906.1271v2.pdf.
I am on page 24, where they derive equations 1.5.67, which are:
##(\gamma^\mu p_\mu-m)u(p)=0## and...
Homework Statement
Two point charges Q1= +5.00 nC and Q2 = -3.00 nC are separated by 35.0cm. What is the electric potential at a point midway between the charges?
Homework Equations
V = Ke(q/r), PE = Vq[/B]
The Attempt at a Solution
This question is from Serway textbook. The answer is...
Homework Statement
This is an example problem I found on khan academy and it didn't have an official problem statement... So I am going to have to make up my own problem statement from what was given. I can link the video if any of you want to see it.
A positive charge 4uC and a negative...
If we imagine two particles A and B. A has positive mass and B has negative mass and initial velocity 0. This happens in a non interfering environment . If both theses has opposite and equal value of mass, shouldn't they be repelling each other?
F=G. (M.-m)/r^2. Value of F should be negative.
Homework Statement
For the molecule CHCl3,
a) Draw the electron dot diagram and structural formula
b) predict the shape
c) predict whether it is polar or non-polar, and justify your prediction. Indicate the positive and negative poles.
Homework Equations
none
The Attempt at a Solution
[/B]...
No one could ever explain to me the mechanism how attraction of positive and negative charge works.
Can you? (Exchange of (virtual) photons only explains repulsion.) An electrical field is playing hide and seek.
I'm so confused, is the voltage reading of the meter gathered by:
positive electrode charge - negative electrode charge = potential difference
I don't get why there is a positive and negative electrode and what they do
I am solving for the square root of a complex number, namely: ##\sqrt{5 -12i}## Let's assume for brevity's sake that I already have the solution ##3- 2i##. This is fine and well, but the book that I am reading goes on to say that "##- (3 -2i)## is an equally valid solution, since there is no...
How would we define positive and negative work in terms of energy? When the force and displacement are in opposite directions, we say the work done by the force is negative. When the force and displacement are in the same direction, we say the work done by the force is positive. However, how we...
Homework Statement
An amount of work equal to 1.5 J is required to compress the spring in a spring gun. ?
Homework Equations
Wtotal = change of KE[/B]
The Attempt at a Solution
W=ΔKE=(1/2)m(Vf² - Vi²)
It sounds like the Vf >0 and would be maximum after the spring is compressed hard and...
Hello, I was looking for some sort of chip/IC that would accept a digital input of say 4-5 bits and that would adjust an output current. I am looking to have a +/-3.3mA current applied to a resistive load. It would also be helpfull (for testing purposes) if I could adjust the inputs so that I...
We have been able to explain the reason for the mass of a particle to a great extend... But till now why are we not getting a clear idea of why does a particle has charge?? What gives a particle its charge??
Simply, is there a difference between a positive charge repelling a positive charge and a negative charge repelling a negative charge. More of what I am asking, is there any special properties that one has over the other, and vice versa.
Homework Statement
(Just for number 1 only - finding electric field) [/B]
Homework Equations
dE = k dq/R^2
sin theta = y/R = y / sqrt (a^2 + y^2)
dq= lamda*dy
The Attempt at a Solution [/B]
I'm confused at the point of calculating the integral from -L/2 to L/2. I got the final integral...
Homework Statement
If a small positive and negative charge are created at rest at a point between electrodes as shown in the figure. In which direction will they move if one would neglect gravity?
Ignore those weird arrows, those are for later questions.
Homework Equations...
The image bellow is the PN junction under equilibrium.
I wonder why there are so many positive and negative ions in N and P types respectively.
For me, I think that these ions should only exist in the depeletion region not outside the region.
Thanks for help.
What happens to the Reimann tensor at the event horizon of a black hole? Do some of the 24 components become zero or infinite?
What happens to parallel transport of a vector on the surface of an event horizon that is different than on a surface outside the event horizon?
I'm newly educated...
Homework Statement
I need to understand how signed multiplication is done in 2's to 10's complement.Homework Equations
The complement D' of a number D with m digits in base r is rm - D.
So, the complement of 010 in binary (2 in dec) is 1000 - 010 = 110 (-2, but 6 if it were unsigned). We add a...
Hello
I am aware of what generates the electric charge of each particle, the virtual fotons around it that the particle generates, and that when two particle interact with each other a foton is exchanged and so forth. My question is though, what generates the positive and negative charge, and...
Does anyone know if I run 12 volts dc at 1 amp power for a distance of 250 feet and one wire is 12 gauge used for positive and other negative wire is 20 gauge will the smaller ground wire affect what the positive wire can carry?
John
Hi
this is my first subject in this forum and i hope you can help
1.we have been given an assignment to analyze this non-ideal op amp with both positive and negative feedback and to be honest i don't even know where to start
i know i should post an attempt of trying to solve but honestly...
if electricity is flow of electrons and also positive and negative charges attract
then why electricity needs a conducting medium.
electrons has mass and it should just travel through vaccum
then why in vacuum electricity cann't travel
please reply!
Hello,
Second term of a geometric series is 48 and the fourth term is 3... Show that one possible value for the common ratio, r, of the series is -1/4 and state the other value.
ar=48, ar^3= 3... so ar^3/ar=3/48 which simplifies to r^2 = 1/16, therefore r = 1/4
Can anyone explain where...
Homework Statement
Problem 2.6.3. in "Foundations of modern analysis", by Avner Friedman. Let f be a measurable function. Prove that f is integrable if and only if f+ and f- are integrable, or if and only if |f| is integrable.
Homework Equations
Friedman defines "integrable" like this: An...
I am not a student of Physics. I want to know. I am curious. I never understood a basic thing. What is the difference between a positive and a negative electrical charge? What characteristics describe the two charges?
Are they just something you mug up as a given example of the duality in the...
I'm designing a portable device running off of 2 AA batteries that requires positive both positive and negative 5v power at the same time. What is the best/cheapest way to achieve this?
How to divide positive and negative charges from each other without them interacting with other matter or charge patterns.
,please answer I only need this to make my ultimate machine
how to determine which is the answer to positive sqrt and negative sqrt in this problem?
substituting works but what if the equation is very long and you can't use calcu or computers
http://i.imgur.com/SkcQZ.png
also is there a way to solve this without squaring both sides?
greetings,
consider a wire which is subjected to AC supply.now consider a point X anywhere on wire.
now what will be the potential of that point during the positive and negative halfcycle of sinusoidal AC?what will be the direction of current?
thanks
Reading some QFT in which we are faced with inhomogeneous equation
(\partial^\mu \partial_\mu + m^2)\phi(x)=J(x)
The solution is given as
\phi(x)=\phi^{(+)}_{in}(x)+\phi^{(-)}_{out}(x)+i\int{d^4 x\Delta(x-x')J(x')
where \Delta is the appropriate Green's function. "in" means the...
These questions, being so basic, were harder to find answers to on the forums (or elsewhere). At least, it was harder to find an answer that satisfied my curiosity. I need a DEEPER, simpler, and more logical understanding of these concepts.:
What does it mean for a particle to have a positive or...
Homework Statement
Could anyone explain to me what exactly is positive and negative control in an experiment?
Homework Equations
The Attempt at a Solution
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...
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
Hi everyone
The Hamiltonian of the Klein Gordon field can be written as
H = \frac{1}{2}\int d^{3}E_p \left[a^{\dagger}(p)a(p) + a(p)a^{\dagger}(p)\right]
and we have
[H,a(p')] = -E_{p'}a(p')
[H,a(p')] = +E_{p'}a^{\dagger}(p')
The book I'm reading states that
What does this mean?
Thanks.
Homework Statement
(a) Determine the reflectivity spectrum R(E) of a free particle of mass m reflected from an infinite jump V(x), where
V(x)=0 if x\leq0, V(x)=-\infty if x>0
The other similar problem is:
(b) Determine the energy levels of a particle of mass m confined to an infinite...
Hello!
I need a help with one question:
Discuss weather any work is being done by each of the following agents, and if so, wether the work is positive of negative.
a) a chiken scratching the ground (what I think is that work is performed as
W=F∆x, and if the chicken moves her leg back and...
You probably think that adding one to zero gives you one. But, let us examine this process a little closer.
Imagine being at absolute negative infinity. I know, you are probably thinking that infinity goes on forever, which indeed it does, and therefore we cannot comprehend the point at...
The U.S. seems caught in a love-hate relationship with the rest of the world. What would you say is our most admirable quality, and what the most detestable?