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.
I'm assuming that the observer witnesses all other particles enter a horizon, be it an event horizon or the particle horizon. Thus the observer's observable universe would contain himself only. Is this understanding correct and can it happen in finite time? Also does such a universe have time...
How Does Reflection Behave In Arbitrary Surfaces
Hi
I am interested to know how reflection would behave in a mirror on a surface of negative [gaussian] curvature.
I tried googleing it and found nothing useful
Thanks
Edit:
Reflection in a sphere behaves like inversion in a sphere...
Identify which of the ff. object will be positive or negative charge
1) Hand and Hair
2) PVC and Tetlon
3) Glass and Poly ester
4) Rubber and rubber
5) Hand and wood
Hello All I'm new to the forum and have a question.
I was looking at the time dilation function and noticed that negative time would be described with imaginary numbers and be a kind of anti-time, albeit that rest mass can not be pushed faster than the speed of light but for the sake of...
https://www.youtube.com/watch?v=jERhPMzqSaE
http://www.cnbc.com/id/44039103"
"More broadly, the downgrade reflects our view that the effectiveness, stability, and predictability of American policymaking and political institutions have weakened at a time of ongoing fiscal and economic...
Homework Statement
Given a circular wire with radius R. Choose the origin in the center of the circle, the z-axis perpendicular to the circle. One halve of the circle contains a positive line charge \lambda, the other halve a negative line charge of the same magnitude.
(a) Sketch the electric...
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?
For example:
i) Someone lifts 2kg flowerpot 1m vertically upward. The work done by the gravity is -19.62 J?
Then, if
ii) A 3kg box on the floor is lifted vertically up onto the head and then lowered down to the shoulder. The shoulder is 150cm while the top of the head is 175cm measured...
Hi,
Iam reading horowitz and hill and came through this paragraph in section 2.03 Emitter follower :
Notice (Section 2.01, rule 4) that in an emitter follower the npn transistor can only "source" current. For instance, in the loaded circuit shown in Figure 2.8 the output can swing to...
Hi all,
I've been using Faraday's law to find the EMF in a coil of wire in a changing magnetic field.
EMF = -N (change in mag flux/change in time) for N loops
I'm finding that the EMF is always positive regardless of whether the change in flux is positive or negative. I'm wondering at...
Protons have a magnetic moment of 2.8 μN, Neutrons have a magnetic moment of −1.9 μN.
What is the meaning of the negative sign? Does the Neutron go a different direction in a magnetic field? How do they know it isn't just upside down? Is there any kind of a visual picture of a magnet that...
Why is the Time component in the Space Time Interval negative?
The space time interval is defined to be:
ds^2=dt^2-dx^2-dy^2-dz^2
or depending on the convention used it may also be:
ds^2=-dt+dx^2+dy^2+dz^2
The equation is defining distance using the pythagorean theorem. This results...
Can a charge, brought into a chargeless world filled with some geometry of conductors and dielectrics, induce a negative potential anywhere in that world?
I feel the answer is no. But I cannot think of a good way to prove it, or even attack the problem.
More explicitly, imagine a world...
Hi yall,
Im trying to understand waves and I am wondering why the velocities are negative sometimes and or positive.
I think that the velocities are negative because of the slope of the wave as it is coming down? I just want to completely understand it and am a little confused.
Like...
Hi,
I am a student who's learning about quantum mechanics. I was reading about the RTD (Resonant tunneling diode) and I got the general idea. However, I was looking at a I vs V graph and came up with a question. Since Resistance = V/I, the inverse slope of the I vs V graph has to be the...
Homework Statement
How much positive and negative charge are in a 50g Tungsten ring?
Homework Equations
Standard atomic weight 183.84
The Attempt at a Solution
From Wikipedia: "Positron emission or beta plus decay (β+ decay) is a type of beta decay in which a proton is converted, via the weak force, to a neutron, releasing a positron (the antimatter counterpart of an electron) and a neutrino.
Isotopes which undergo this decay and thereby emit...
Might be a naive question.
In many places, specially in the Hubbard model, people use a minus sign before the tight-binding hopping amplitude. What does the negative sign signify for? Any special intention?
Thanks.
What am I finding to be confusing..
The graphs of Millikan's data were straight lines with equal slopes. The graph was plotted maimum kinetic energy (eV) versus the frequency of the wave. This was the graph that produced the linear relationship from the photoelectric effect.
What does it mean...
can somebody simply explain what is meant by NEGATIVE QUANTUM STATES , as given by dirac in his theory?i know its not as SIMPLE as i want it to be , but still I would like to know its significance in the most basic way!
Hello everyone.
I understand the concept of work in general, but the concept of negative work still somewhat baffles me. One of my main problems is this: according to my textbook, 3 conditions must be met in order for work to be done, and one of them is "at least part of the force must be in...
Sometimes to understand things I need to come up with ideas and have them shot down.
This is what I am doing here.
I have been informed that the Cashmeir effect may not be due to negative energy so I have an idea for an additional experiment. Suppose we were to make a "box" with little...
Hi PF, just a quick question that always seems to confuse me.. when should 'g' be negative in equations? Intuitively, I tend to always substitute -9.81 m/s into equations but it seems that this can be incorrect in special cases.
Are there certain situations where 'g' should be or shouldn't be...
what is mass? and is negative matter really possible
i wasnt sure if i should post it in this forum or not but i thought the second part of the title refers to particle physics so i posted this here.
so as the title suggests i was wondering what is mass. i have heard answeres like it is a...
Hi, nice forum. I was thinking how I would go about proving with an example, that negative Gs are occurring?
Homework Statement
Say a stunt pilot is doing a maneuver that will expose him to negative Gs. It could look like this...
Circuit can supply "negative voltages"?
I read an article trying to understand voltage dividers better.
I then read this quote that threw me off!
Now, what does it mean that a circuit is designed to supply both positive and negative voltages? I'm pretty new to electricity. All I need is...
The negative pressure generated in the Cashmeir effect suggest that negative energy can exist in small spaces between non-conducting plates. How much negative energy exist in a given amount of space as measured in units that refer to energy (as opposed to units of force created by the Cashmeir...
I was just reading a book on low-temperature physics and stumbled upon a graph that shows the energy of liquid Helium-4 in relation to its molar volume. The graph includes both zero-point energy and the potential energy of the liquid, and the latter goes steeply (basically a vertical line) from...
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
Getting Rid of Negative Exponent!
Homework Statement
So I am solving a Diff Eq ( separable equation) and I am down the the last step. After integrating both sives and solving for y I am left with y^(-2) on the left hand side. How do I finalize it and get rid of negative 2 expononent...
2 parts:
1. What does it mean if you get a negative gauge pressure value when calculating from manometer containing compound liquid? When calculating absolute pressure how does atmospheric pressure affect this negative pressure ie. atmospheric pressure opposes the direction of force?
2...
i am only a year 11 student so i don't know much about the Theory of relativity
i just heard that if we can travel at the speed of light our time will be slower than the other
so i am just wondering if we can travel at a negative speed of light that means that we can go back in time?
Hi,
I am trying to estimate variance for negative Binomial distribution using
maximum likelihood estimation and Expected (Fisher's) information to determine its variance. I know what variance is for this distrubution but I cannot derive it.
Here is my solution. Any comments and...
Why is int(1/(1-x))=-ln(abs(1-x))?
If you substitute u=1-x
then
int(u)=ln(abs(u))=ln(abs(1-x))
Also, in this question you're trying to find the particular solution y=f(x) to the given differential euqation with initial conditions
f(-1)=2
dy/dx=6x^2-x^2y
d^2y/dx^2=-12.
So i get to...
Let's say that negative mass existed, what might it look like? Could it look like an ordinary rock stuck in the ground? If so, what would happen if you tried to move it around? If it moves in the opposite direction it is push then wouldn't it be impossible to move it in any direction? Would it...
Hello Everyone,
My statistics is terribly rusty so I am turning to all of you for assistance! I am in the process of reviewing my old text but I figured this may be quite a bit quicker.
Homework Statement
Suppose "x" is normally distributed with "mu_1" and "sigma_1." Now suppose x is measured...
Gamma Function on negative Fractions!
If we take a look at the Gamma Function and evaluate the integral by parts then we will get infinity in the first step of Integration by Parts eg:
Integral e^-1*x^-5/3 Limits being 0 to Infinity as usual! If we try to integrate this we will get...
The Klein Paradox is the name given to the following prediction of Klein Gordon's equations. If you send a current of electrons against a potential barrier of height V such that the energy of the incident electrons is less then V - m, you should observe a current of positrons coming out of the...
Homework Statement
I am working with cosmology and expansion.
Obtain dz/dt as a function of z and H_o only. What is the sign for dz/dt and why?
z is the redshift and H_o is the Hubble constant.
Homework Equations
The Attempt at a Solution
So I found the equation for dz/dt =...
I would appreciate some clarification on working with lenses and virtual objects (when the object distance do is negative).
I'm not sure what happens when the do is negative and you get a positive value for di. On which side of the lens does the image go?
Normally, for a lens, if di is...
as we know at zero degree temp. water condense to form ice. so what will be the relative humidity of a chamber at a temperature below zero degree temp.?
will it be nagative or what?
what are the restrictions (if any) on y=1/x^(-2)?
is it equal to just x^2 so no restrictions or what
it is have hole at x=0?
or do you change too all positive exponents before looking at restrictions?
what exactly are the exponents rules that govern this stuff
so confused