In mathematics, a negative number represents an opposite. In the real number system, a negative number is a number that is less than zero. Negative numbers are often used to represent the magnitude of a loss or deficiency. A debt that is owed may be thought of as a negative asset, a decrease in some quantity may be thought of as a negative increase. If a quantity, such as the charge on an electron, may have either of two opposite senses, then one may choose to distinguish between those senses—perhaps arbitrarily—as positive and negative. Negative numbers are used to describe values on a scale that goes below zero, such as the Celsius and Fahrenheit scales for temperature. The laws of arithmetic for negative numbers ensure that the common-sense idea of an opposite is reflected in arithmetic. For example, −(−3) = 3 because the opposite of an opposite is the original value.
Negative numbers are usually written with a minus sign in front. For example, −3 represents a negative quantity with a magnitude of three, and is pronounced "minus three" or "negative three". To help tell the difference between a subtraction operation and a negative number, occasionally the negative sign is placed slightly higher than the minus sign (as a superscript). Conversely, a number that is greater than zero is called positive; zero is usually (but not always) thought of as neither positive nor negative. The positivity of a number may be emphasized by placing a plus sign before it, e.g. +3. In general, the negativity or positivity of a number is referred to as its sign.
Every real number other than zero is either positive or negative. The non-negative whole numbers are referred to as natural numbers (i.e., 0, 1, 2, 3...), while the positive and negative whole numbers (together with zero) are referred to as integers. (Some definitions of the natural numbers exclude zero.)
In bookkeeping, amounts owed are often represented by red numbers, or a number in parentheses, as an alternative notation to represent negative numbers.
Negative numbers appeared for the first time in history in the Nine Chapters on the Mathematical Art, which in its present form dates from the period of the Chinese Han Dynasty (202 BC – AD 220), but may well contain much older material. Liu Hui (c. 3rd century) established rules for adding and subtracting negative numbers. By the 7th century, Indian mathematicians such as Brahmagupta were describing the use of negative numbers. Islamic mathematicians further developed the rules of subtracting and multiplying negative numbers and solved problems with negative coefficients. Prior to the concept of negative numbers, mathematicians such as Diophantus considered negative solutions to problems "false" and equations requiring negative solutions were described as absurd. Western mathematicians like Leibniz (1646–1716) held that negative numbers were invalid, but still used them in calculations.
A consequence of Coulomb's law is that oppositely charged particles have a negative potential energy. I'm having trouble undsrstanding how anything can have a negative potential energy and what consequences that has. Does it just mean the change in potential energy is negative or is it a matter...
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...
Was reading this article:
https://phys.org/news/2018-01-device-negative-massand-lasers.html#jCp
The article claims that these guys have created negative mass? If that's true, isn't that ground breaking? It's one of those extraordinary claims that needs extraordinary proof, doesn't it?
Or is...
Matter with negative mass, herein called “negative matter”, is different from antimatter.
P.A.M. Dirac, on theoretical grounds, proposed the existence of antimatter, and its
existence was later confirmed by experiment. Antimatter is the opposite of ordinary
matter in some ways, but just as...
Homework Statement
A student pushes a 0.65kg box Ali g a desk. When he stops pushing the book, it moves 85cm before stoping (slowing down in this period). Coefficient of friction between book and Table is 0.27.Calculate the work done on the book by the friction. Should it be positive or...
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...
Well for awhile at least. I'm a bit surprised they couldn't export the excess.
The Independent: Germany energy consumers paid to use power over Christmas as supply outstrips demand.
http://google.com/newsstand/s/CBIwn6XOoTc
My chemistry course says that work done by the system is negative, but physics course says that work done by the system is positive, I'm sure I'm missing something and I really need to understand it. Thanks.
If we have the normal KG scalar field expansion:
$$ \hat{\phi}(x^{\mu}) = \int \frac{d^{3}p}{(2\pi)^{3}\omega(\mathbf{p})} \big( \hat{a}(p)e^{-ip_{\mu}x^{\mu}}+\hat{a}^{\dagger}(p)e^{ip_{\mu}x^{\mu}} \big) $$
With ## \omega(\mathbf{p}) = \sqrt{|\mathbf{p}^{2}|+m^{2}}##
Then why do we associate...
Hello!
I've been working on a few soil based MFCs and I have been monitoring my voltage and energy output for a week now. I've made the electrodes by covering stainless steel metal meshes with activated carbon using epoxy. I've gotten some funky results as attached.
As you can see... the...
Homework Statement
Homework EquationsThe Attempt at a Solution
I first said it's B, since force throws up = positive.
gravity down= also positive, please help asap thanks
My question is that why is the negative charge on the oxygen atom with the single bond, why not on the oxygen atom with the double bond? I am confused.
Source: https://chem-net.blogspot.in/2012/01/simple-procedure-for-writing-lewis.html
I am confused how a charge could have negative work done.
To clarify, I was doing a problem earlier in which a positive charge and negative charge are moving towards each other. I used the equation
work = Δv * q
And when I was doing this, the change in electric potential, Δv, was negative, and...
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...
i've built a bridge rectifier with a Zener Voltage regulator.
12V peak secondary
3300uF Capacitor
1k ohm load
1k ohm series resistor for the zener
and a 1n4728A Zener diode.
i'm getting a 2.8V steady voltage, but when i measured the current going through the load with my DMM it's measuring...
Homework Statement
[/B]
Homework Equations
Adiff(single-ended)= 1/2gm*ro||Rd
β=R2/(R1+R2)
The Attempt at a Solution
I am really confused as to how to find A. I know the feedback of the circuits around the R2 and R1, but I don't understand how the open loop gain can be found. Can someone...
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.
Is possible and what does it mean if a chemical potential is negative?
I mean that for boson it means that in environment is "needed" boson (photon) and is possible to create him. Is it true?
And what about for fermions? Could it mean that it is pleasent for environment to creat some fermion? Or...
The smoothed Weyl tensor can look like space that contains a non-zero Einstein tensor. To verify this, consider that gravitational waves carry mass away from (say) a rotating binary, so the apparent mass at infinity of a large sphere containing a radiating binary will be greater than the mass...
I sealed my attic door and a set of 3 old windows downstairs with plastic. When everything else is closed up the two sets of plastic become extremely tight and you can see/feel the pressure pushing the plastic into the house. Almost to the point of ripping the tape off holding the plastic. Today...
Mod note: Fixed all of the radicals. The expressions inside the radical need to be surrounded with braces -- { }
(This question is probably asked a lot but I could not find it so I'll just ask it myself.)
Does the square root of negative numbers exist in the complex field? In other words is...
Homework Statement
Prove that {##x \epsilon \mathbb{R} : x^2 \ge 1##} is "not" bounded below.
EDIT: I Looked closely and realized there is a "not" that we all had to write in...sorry if you lost some time..
Homework Equations
Defintion: We say a nonempty subset ##A## of ##\mathbb{R}## is...
I'm a bit confused as to how to imagine a negative sensible heat flux near the Earth's surface. Negative means that sensible heat is moving towards the surface. My book states that that would mainly occur at nighttime.
During day there is a positive sensible heat flux and sensible heat moves...
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]...
Homework Statement [/B]
Homework Equations
Snell's Law:
n1sin(i)=n2sin(r)
Critical angle=sininverse(n1/n2) [**only works when n2>n1]
If a light beam is incident at an interface of 2 mediums(with r.i n1 and n2) at an angle greater than the critical angle,the interface acts as a...
So in my Physics lab, we divided into groups and our task was to throw darts on a target containing 13 bins. The bins look something like the image below. At the end, our class combined our average, standard deviation, and standard error. I made a Gaussian Distribution and I noticed that the...
Now, I know that it is theoretically possible for negative mass to exist and for negative energy to exist. But any gravity would act on all objects and all energy, no matter if that mass and energy is positive or negative. So negative gravity would for example, pull a person upwards. Now yes, I...
Homework Statement
A car is moving with a constant velocity of 18 m/s for 5 seconds, if in the next 5 seconds it travels a distance of 40 m, what is its final velocity?
Homework Equations
Δx= vit+ 1/2 at^2
vf= vi+at
vf^2 = vi^2 + 2a (Δx)
The Attempt at a Solution
So I tried doing it different...
In the case of lifting a box, I know potential energy is negative because negative work is done by gravity. What does the negative part of -PE denote? Does it denote the direction of the energy or does it mean that energy is being lost? But how is energy being lost if the box gains more...
In physics we cannot easily imagine “negative” energy for a particle (not a field) in order to have “negative” mass, although the first concept of Dirac for antiparticles was that they were “holes” that were opposite to particle existence and there was a minus in front of mc2.Regardless of...
Hey! :o
Can the minimum of the average variable cost function be negative? (Wondering)
Suppose we have the cost function $K(x)=x^3-9x^2+11x+100$.
The variable cost function is then $K_v(x)=x^3-9x^2+11x$. The average variable cost is $k_v(x)=\frac{K_v(x)}{x}=\frac{x^3-9x^2+11x}{x}=x^2-9x+11$...
Homework Statement
You are in a large store that has escalators connecting its floors. The stairs of each escalator move smoothly and steady either uphill or downhill as they carry passengers between floors.
You get off the "up" escalator on the second floor and board the "down" escalator. This...
Going through a problem and and I keep getting it wrong and I'm not sure why.
In a part of the problem, the expression ##\left(-3\right)\left(-r^4\right)\left(-s^5\right)## comes up and the solution that it's giving me is ##-3r^4s^5##
Wouldn't the last factor be ##-s^5## since the power of a...
Homework Statement
Homework Equations
Differential of a product:
$$d(uv)=u\cdot dv+v\cdot du$$
The Attempt at a Solution
$$dV=\pi \left[ -\frac{1}{x}x^2+2x\left(-\frac{x}{3} \right) \right]dx=-\pi x^2dx$$
If dx>0 dV<0, it's wrong, the volume increases
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.
Homework Statement
In this problem, the solution says that aB= -(aA/6). But from what I know, acceleration is positive whenever an object is speeding up in the positive direction or when an object is slowing down in the negative direction. According to the problem, car B is slowing down and...
Hey guys, I am seriously confused by this problem.
3/4 [ 5/6 ( -18/25 ) + 1/2 ]
I would appreciate it if someone shows me the step by step process.
Thanks in advance :)
Auto-Search gives me some hints.
I did a Google for "Hydrogen Ion Generator" and got a load of hits about "Negative Hydrogen Ion Generators". They almost seem to be 'fusion specific'. Are they used because the required end result is a neutral beam of Hydrogen/Deuterium for injection into the...
I have this brain worm and it's been bugging me for ages. I don't know enough about anything to be able to answer this but when I heard a theory that an electron can be in 2 places at once but then appears to be in a specific location when observed I started wondering how this could be possible...
Sorry if the title was a little vague, character limits. The question at hand is this; If you were to accelerate an object to near speed of light, time around it would speed up, thus forward time travel. We all know this and I am no expert in this area but am incredibly curious. (Assuming we can...
I was reading the wikipedia page on the twin paradox (https://en.m.wikipedia.org/wiki/Twin_paradox). It says:
The mechanism for the advancing of the stay-at-home twin's clock is gravitational time dilation. When an observer finds that inertially moving objects are being accelerated with...
Hi,
While solving homework problems, I start by defining a positive-y direction and a positive-x direction. Let's say up and to the right. Until now, I've applied this same rule to all objects in each problem, no matter the direction the object moves. But it seems I have not understood this...
What is the relationship between negative energy, negative mass and antiparticles? I have read some articles but I am still confused. Does negative mass exist? Does negative energy exist with the exception of the Kasimir effect which I understand. Are antiparticles really only the negatice...
My question is:
If gravitational potential energy is normally negative, and E=m•c^2, doesen't that means that negative mass could exist?
(I don't know much about general relativity so please explain as simple as posible)
I understand that if you have a function in which you want to determine the full (i.e. account for positive and negative values) integral you need to break down your limits into separate intervals accordingly.
Is there any way in which you can avoid this or is it mathematically impossible? If...