Negative Definition and 1000 Threads

Three negative point charges lie along a line as shown in the figure. figure: http://tinyurl.com/7xppvc8 Find the magnitude and direction of the electric field this combination of charges produces at point , which lies 6.00 from the charge measured perpendicular to the line connecting the...

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...

Two parallel plates are 2.0 cm apart and the electric field strength between them is 1.0 × 10^4 N/C. An electron is launched at a 45 degree angle from the positive plate. What is the maximum initial speed v0 the electron can have without hitting the negative plate? i think the answer is...

Hello! I am playing around with an equation (i.e. it's not a textbook question), and I arrived at the following problem: The equation is: A = -1*\sum_{i=1}^{N}*\log_{N}(P_{i})*P_{i} Pi is less than or equal to 1 and more than or equal to 0, and is a probability of finding an object in a...

One of the discrete Fourier transform (DFT) properties (symmetry property) is that: x^*[-n]_N \stackrel{DFT}{\leftrightarrow}X^*[k] where * means conjugate, and [.]_N means modulus N. What is the meaning of modulus of negative numbers? Thanks in advance

Homework Statement The work done by an external force to move a -8.5μC charge from point A to point b is 15x10^-4 J. If the charge was started from rest and had 4.82x10^-4 J of kinetic energy when it reached point b, what must be the potential difference between a and b Homework Equations...

This has been bugging me for a long time! Now if electrons are -Q and the V is basically what energy is added to that Q how do you define the voltage as being - or +. For example in a computer system, the data cable has + and - negative voltage, so is the polarity switch at ether end on the...

Homework Statement Two teams, A and B, play a series of games. If team A has probability .4 of winning each game, is it to its advantage to play the best three out of five games or the best four out of seven? Assume the outcomes of successive games are independent.Homework Equations...

why there is no answer when negative value is being square root? e.g: square root of -9 when i try to find answer from calculator, ''math error '' appears.. so is there an explanation for this question?? this question may looks so weird..but i m juz asking out of curiousity..

Hello, I was investigating a system with N indistinguishable particles, each of which can have an energy \pm \epsilon, and using the grand canonical ensemble, i.e. \Xi = \sum_{N=0}^{\infty} e^{\beta \mu N} Z_N. But my entropy formula is S = \left( \textrm{a couple of $\sim N $ positive...

Why did we define negative numbers? They don't exist in real life. Was their purpose to add negative numbers instead of subtracting positive numbers? Why can't we have more positive numbers that are twice as positive as regular positive numbers? Or numbers that are twice as negative as regular...

I have a quick question. I've been trying to search for an answer, but I'm probably looking in the wrong places. Is it valid to have negative off-diagonal elements in a density matrix? Thanks!

I am studying Integer Modulo in my Cryptography and Data Security class. We are dealing with mainly modulo 26 [the alphabet] right now. I understand if it is addition or multiplication you just take the remainder of the result divided by, let's say 26 in this circumstance. ie: (5+25)mod26 = 4...

Homework Statement 1 - A person moving toward the motion sensor with constant velocity.. 2 - A person moving away from the motion sensor with constant velocity.. Homework Equations For both statement above.. Is the velocity positive or negative? The Attempt at a Solution For...

I've been trying to find out what the definition of negative pressure in the context of General Relativity. There are some information on negative pressure and I found this: https://www.physicsforums.com/archive/index.php/t-299495.html The starter of that thread also doesn't know what the...

Homework Statement I am taking the readings of voltage/current in a small induction generator; the readings are conveyed as negative on the voltage/current sensors on my data-logger, and positive on the multimeter in both areas. When the magnet passes through the coil, and power is generated...

if f(x)modg(x) is valid(means , if it yield a remainder) then , can there be negative powers of x in f(x)? for example is (x-29)mod(x2 - 3) possible ? can we do modulo division like this or is it strictly defined only for positive powers of x?

What's the meaning of negative temperature if temperature can only be a scalar? Why the construction of negative temperature in degrees Fahrenheit?

Homework Statement A square coil of wire of side length 2a lies in the yz plane. A current I flows through the loop. The x-axis is defined such that it passes through the centre of the loop, with the loop boundaries being at z±a and y=±a respectively. Given that I flows in a direction...

Lets see if I understand this one correctly. Basically negative resistance is when an object actively draws electrical current through it. The object almost encourages current to flow through it? Thanks AL

Hey, there's this thing I can't wrap my head around. Let's say we have a negative binomial variable x, with parameters p and r. That is, x is the number of failures we get before the rth sucess, while looking at random bernolli variables with sucsess rate p. It can be shown that...

I want to make the above claim in a physics paper for my intro to physics class, but first I want to confirm if it is absolutely correct. My reasoning goes that Force, acceleration, and velocity, can be negative, but mass and kinetic energy cannot be. Is my conjecture sound?

I've heard this theory, based on the assumption that if negative mass objects exist, they would travel faster than light. I planned on mentioning this in a physics paper I have to write for my class, but I just realized that I have no idea what formula shows this correlation. Can somebody help...

Homework Statement A car with a mass of 1.0 X 103kilograms is moving with a speed of 1.4 X10 2m/s. The impulse required to bring the car to rest is? Homework Equations impulse = change in momentum... The Attempt at a Solution the answere is 1.4 X 105 N X S or is it the negative...

A proton (m = 1.7 * 10–27 kg, q = +1.6 * 10–19 C) starts from rest at point A and has a speed of 40 km/s at point B. Only electric forces act on it during this motion. Determine the electric potential difference VB-VA. Here is what I did: V = \frac{U}{q} U = qV = \frac{1}{2}mv^2 V_B - V_A...

I recently had a test (precalc) where we had to solve log(x)-log(x+4)=2 for x. The answer comes out negative. I understand that in precalc we are defining the logarithms for just positive numbers, but- Is it ever justified to define a logarithm for all numbers, both negative and...

You attend a multiple choice question exam, and you have n (say 10) questions whose answers you don't know at all. There are 4 choices in each question. A correct answer yeilds 1 marks. An incorrect answer has penalty of -0.25 marks. Is it wise to attempt all the questions in random? It...

This is actually not a full problem, just a part of one I'm having trouble with: Homework Statement If I have a acceleration vector, say [ bk^{2}e^{kt} - bc^{2}e^{kt} ]e_{r} + [ 2bkce^{kt} ] e_{θ}. How can I find its magnitude? Homework Equations Mag vector |a| = (a^2)^(1/2) The Attempt...

I was thinking, can an object have negative mass? If an object with positive mass needs infinite energy to go at the speed of light, would an object with negative mass need infinitely negative energy (if negative mass were possible, this would be possible too right?) If an object had negative...

Hello everyone I have trouble understanding the idea of multiplying two negative numbers. Why is product of such multiplication a positive number? Its so confusing.

Hi all, I know that there are many ways to derive the equations for SHM. I'm clear on how the negative signs come out when we use derivatives; but I've a problem understanding how the negative signs come into play using the reference circle. 1. If the centripetal acceleration is a = rω2...

Can an up quark absorb a negative W particle and become a strange quark? I know s can turn into u via the opposite process (emission of positive W), but can the interaction go the other way? This arises when trying to draw the Feynman diagram for the rather unlikely decay B^+\to...

Does antimatter (negative matter) have "negative mass"? If not, why is this so suspected? And could anything theoretically have negative mass?

Sorry if this sounds a bit mixed up. When I was growing up, in the late 1990's, popular science books about cosmology use to describe the average mass-energy density of the universe, especially comparing it to the critical density. Those books used to say that visible matter gives too-low...

A damped oscillator is described by the equation m(x'') + b(x') + kx = 0, where the damping force is given by F = -b(x'). Show that the rate of change of the total energy of the oscillator is equal to the (negative) rate at which the damping force dissipates energy.

I was wondering if virtual anti particles had a postulated anti gravitational charge if that would be inconsistent with Hawking radiation as virtual anti particles would always be ejected from the vicinity of the Schwarzschild radius whereas virtual particles may or may not be ejected depending...

Michio Kaku mentions in his TV series "Physics of the Impossible" about negative mass being able to repel gravity. I haven't heard much about this before. How would the negative mass affects the geodesic in spacetime manifold? Perhaps by causing negative curvature of spacetime? Would this...

in acceleration time graph when the acceleration is constant. Then at an instant it has negative acceleration. Does this mean that the body is decelerating or it is accelerating in the opposite direction. eg. http://hyperphysics.phy-astr.gsu.edu/hbase/mechanics/motgraph.html {last graph}

actually i have worked out the question..but i doubt about my answer..can anyone help me to verify this question please..kindly please refer to the attached files whereby i attached questions as well as my workings also...i really need help please..thanks in advance ..if possible may i have the...

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 am having an issue with why negative numbers work the way they work. For instance why does 5 - (-2) = 7 Why do two negatives make a positive when you subtract them? For me that equation reads 5 apples and you take away -2 apples which to me doesn't really make sense because in real...

Nevermind all good.

Hi I'm doing simulations in preparation for experimental measurements of decoupling capacitor parasitic inductance. I've done simulations of two port measurements, in mentors hyperlynx, of parallel capacitors on small power planes. These have given me s2p files that I've converted to...

Hi I know that the sphere has positive curvature everywhere, and the torus has positive an negative curvature. Is there a space homeomorphic to the sphere such that this space has negative curvature everywhere? And, is there a space homeomorphic to the torus such that the curvature is always...

Homework Statement Consider the linear inhomogeneous second order two point BVP; -a(x)u''(x) + b(x)u'(x) = f(x) for 0 < x < 1 for some functions a, f, b where a(x) > 0 for all x 1) If f(x) < 0 for x = [0,1], show that u(x) attains its maximum value at one of the two end points x = 0, 1. -...

I have calculated magnitude of acceleration of an object slowing to a stop to be: -5.1m s^-1. I then had to find the magnitude of the unbalnced force applied to the object for it to stop which i found to be: So F= 1500 kg * 5.1 m s^-2 Which equals 7650kg m s^-2 Which...

Hello Everyone! I have recently been attempting to understand negative resistance circuits(on a practical level at least to start). I've pulled up a few websites giving actual circuits to demonstrate the principle, but still can't quite understand it. Every circuit example so far shows either...

"Beta particles are high-energy, high-speed electrons or positrons emitted by certain types of radioactive nuclei such as potassium-40. The beta particles emitted are a form of ionizing radiation also known as beta rays. " Negative charges also contain electrons, Beta particle are...

Hey guys So if I lift a book from the ground it gains potential energy. I do work on the book and when I release it the potential energy that I gave the book pulls the book back down to Earth. However I was looking at a potential energy formula for planets which was V = -GMm/r But...

Homework Statement Can you have a negative angle, or do you just assume absolute numbers? Your coach tells you to turn south for 10.0m and then turn and run east 15.0m. How far must the ball be thrown from where you started to where you ended? Homework Equations a^2 + b^2 = c^2...