Negative Definition and 1000 Threads

Homework Statement An object is acted on by the force shown in the picture shown below: What is the final position of the object if its initial position is x = 0.50 m and the work done on it is equal to -0.29 J? Initial position = Xi = 0.5 m Work = W = -0.29 J Force = F displacement = d...

What would happen to a metal superconductors taken below zero to a negative temperature? Would it loose its superconductivity?Regards, JDM

I'm using Pascal's (n choose k) method for calculating the coefficients of the terms of a binomial expansion. However, if the exponent is a negative integer, how can one use this method, seeing as factorials for negative integers are undefined. For example, how could one determine the...

Homework Statement Let EPE be change in electric potential energy so if a positive charge is moving towards the negative terminal with the electric field it would mean that it is losing PE therefore work = - EPE, and if a negative charge is moving against the electric field towards the...

I was reading about negative temperature here http://www.nature.com/news/quantum-gas-goes-below-absolute-zero-1.12146 and how the state is "hotter than hot" and thought of fusion.Since you need very high temperatures for fusion does the discovery on negative temperatures bring fusion as a power...

or, Why are there so few polyatomic cations? What about the mechanics of an atom makes it so?

A theorem in my textbook states the following: For every n=0,±1, ±2, --- the formula ln z=Ln z ± 2nπi defines a function, which is analytic, except at 0 and on the negative real axis, and has the derivative (ln z)'=1/z. I don't understand why the logarithm isn't analytic for negative real...

<< Moderator note: This thread is missing the homework template due to originally being posted in another forum. >> hello everyone, this is my first post and I am looking for some help. in my lab we did an experiment to calculate specific heat values for various metals using a calorimeter. the...

Hey guys, can you help me with the proofing of E(X) = r/p and Var(X) = rq/p^2

What is "Negative Gradient" ? and what is "Gradient Descent Method" ? What is the difference and relationship between them ? What is the benefit each of them ?

Not sure if this is the right section but I believe it'll be moved if not. :) Anyway, in my physics laboratory, we build an RC parallel circuit. we measured some things here and there that would help us draw the tan of the phase φ as a function of the frequency. The problem is, instead of...

I hope I'm doing this correctly! I'm having problems understanding negative exponents and how they work... I have this problem, (x^-2)/(x^-2 + y^-2) I don't understand how the answer could be, (y^2)/(x^2 + y^2).. Maybe I'm doing something incorrectly? :/

Homework Statement The physics of circular motion sets an upper limit to the speed of human walking. (If you need to go faster, your gait changes from a walk to a run.) If you take a few steps and watch what's happening, you'll see that your body pivots in circular motion over your forward foot...

Hi, Say I have a variable 'x' which has the polar value 10@-75°, would '-x' be -10@+75° or 10@+75° as I am a touch confused as to which bit I have to invert

Suppose the box (stone, bullet..., $$m =1$$) is not moving upward because of a lift, but has been shot and has $$v = 20m/s$$ and $$KE = 200 J$$ Gravity is doing negative work and subtracting energy: $$F = -ma = 10 \cdot 1 = -10 N$$ We cannot use the palallelogram here as KE is not a force, how...

This is in reference to a POTW, http://mathhelpboards.com/potw-secondary-school-high-school-students-35/problem-week-135-october-27th-2014-a-12786.html. The logic behind this problem is simple, the number 2^{2^x} can only have factors of 2. But (n + 1)^3 - 1 contains an odd factor. Great...

Is there any evidence that suggests there can be more than just positive and negative particles

I was trying to determine the best oxide thickness and material for maximising the contrast of one atom thick material layer on top of silicon chip. Using Fresnel equations I was able to do plot the contrast with respect to oxide thickness and wavelength, but alas, contrast seems to be sometimes...

Is there any difference between light produced by a positive charge and light produced by a negative charge?

I'm confused by classic description of work and negative work. If someone pulls (slowly) on a rope to lift a bucket in a well, I understand that the person is doing work on the bucket and gravity is doing negative work on the bucket. So, the net work is zero. But if the net work is zero...

Hi all, I'm looking for physical and mathematical explanations for a phenomenon I've noticed when working with rotated material properties relative to an XYZ coordinate system. For certain rotations (~40 to ~50 degrees) about a single axis the S12, S13, or S23 components of the compliance...

Homework Statement An object changes its velocity from 10 m/s [W] to 20 m/s [W] in 4.0s. An object changes its velocity from 20 m/s [W] to 10 m/s [W] in 4.0s. Homework Equations N/A The Attempt at a Solution I'm thinking the first one is positive acceleration and the other one is negative...

In the book Automatic Control Systems, Benjamin C.Kuo, 7th edition, on page 548, he says: https://imagizer.imageshack.us/v2/720x154q90/540/ML8zmu.jpg He is doing an analysis of the following transfer function: http://imagizer.imageshack.us/a/img911/4839/XPKxoO.gif Mr is the maximum value...

What would GRT look like if negative masses existed? What would be the "Schwarzschild" metric, etc.?

Hi! (Smile) I am given this definition of the field of fractions of the p-adic integers: $$Q_p=\left\{ \frac{r}{s} \mid r, s \in Z_p, s \neq 0\right\}$$ How can I show that: $Q_p$ consists of the sums of the form $\sum_{i=-k}^{\infty} a_ip^i$, where $i$ takes at least one negative value ...

How often does this happen? It seems like something that should happen more! http://neuro.plos.org/2014/10/13/this-weeks-most-discussed-plos-neuroscience-article-the-influence-of-partner-specific-memory-associations-on-picture-naming-a-failure-to-replicate/

lim x-> -(infinity) = x + sqrt(x^2 + 2x) I know that you're supposed to multiply and divide it by it's conjugate and that the answer is -1. But I don't understand how the denominator x - sqrt(x^2 + 2x) = x + x*sqrt[1+(2/x^2)] = x[1+sqrt(1+(2/x^2)].

Homework Statement A spring system consists of two parallel springs on top and a single spring connected to them on the bottom as shown: http://i.imgur.com/hgMr12U.png If the system is extended by 7 cm (i.e. x = 0.07m), F = 5N and k2 = 10 N/m, explain why the value of k1 is unrealistic...

Show that all real roots of the polynomial $f(x)=x^5-10x+38$ are negative. Note: I know this is a fairly easy challenge, but it's good to see how different approaches can be generated from different people so that we can learn from one another. :o (Yes)

Homework Statement A simple method for determining the focal length of a negative lens is shown below. Prove this is true. Homework Equations The Attempt at a Solution The linear magnification formula relates magnification, the distance from the lens to the image (i), the distance from...

HI, I have been going through dirac's paper on quantized singularities in the electromagnetic field and there he referred to a problem of negative kinetic energy of electron, what does it mean? I am going to make a presentation on magnetic monopole next month so I need an explanatory answer...

I don't understand why the force of weight is always positive. Doesn't gravity point down, so isn't a = g = -9.8 m/s2? I understand that people always say it's because you can choose the positive and negative directions, but why change g to be positive in these weight situations and not in...

Homework Statement Q1= 200 C Q2=400 CHomework Equations Qtotal= Q1+Q2 ? The Attempt at a Solution Qtotal=Q1+Q2=400-200=200 C Is it possible to connect the positive plate of C1 to the negative plate of C2 and vice versa without the capacitor getting explode ?

What would the velocity and acceleration be if a person was tossing a ball upward but downward direction is positive? When the ball was falling down, what would the velocity and acceleration be?

Well can someone review this? KG equation: \square \Phi + m^{2} \Phi =0, ~~ m^{2} <0 \Rightarrow m=i \mu would lead to the form: \square \Phi = \mu^{2} \Phi . I'm trying to think if applying the same solution as in KG can also happen here... Also for on-shell particles, I seem to be...

1. Determine the relative and absolute uncertainties of R-2 if R is measured to be 4.5 ± 0.005 m 2. The attempt at a solution So according to what I know so far, multiplication and division of uncertainties requires the addition of relative uncertainties... First I tried to get the...

As attached, I know basic concept between Positive and Negative PR But, I confirm this message; Negative resists were popular in the early history of integrated circuit processing, but positive resist gradually became more widely used since they offer better process controllability for small...

I only see positive factors in my book. Example: 2 and 2 are factors of 4. But aren't -2 and -2? Is there some unspoken rule in math that only positive factors count? Thanks!

In a vacuum under standard gravity, an anchored spherical metal electrode is brought to +1,000,000 volts relative to the distant walls of a much larger chamber. (I'm a new user; hopefully this will display as attachment 1) Therefore, electrons that fall through a small gap in the electrode...

So there I was thinking, if the mother was Rhesus Negative and she had a Rhesus positive baby, her antibodies would cross the placenta and attack the Rhesus positive baby's red blood cells (assuming second child). Then I thought, well, what if the mother was Rhesus positive, and the baby was...

hello! I want to know what happens, what means, what the properties are etc of a negative exponent I read on wikipedia "When n is a negative integer and b is non-zero, b^n is naturally defined as 1/b^−n" So based on the above, 3^-2 = 1/3^2 1) Is this correct? 2) Why does this...

hello why "you can’t take the logarithm of a negative number or of 0" ? thanks!

Homework Statement Var(ax^2 - x ) can anyone please help me with part iii) ? i know that VAR (x) = E(X^2)- ( E(X) )^2 ... But I get my E(B^2) = 6875/4 , whereas my E(B) = 5125/12 , where my B= 3X^2 - X, i take E(B^2)- ( E(B) )^2, MY ANS IS NEGATIVE . WHICH IS WRONG! i have attached my...

The Function To Be Programmed \sigma_m=\frac{4(n_r^2 -1)J_m(n_r k R)}{\pi^2kD_m^+(kR)D_m^-(kR)} where D_m(z)=n_rJ'_m(n_rz)H_m(z)-J_m(n_rz)H'_m(z). The '+'/'-' superscripts indicate the limits as z approaches the branch cut, which lies along the negative imaginary half axis, from the positive...

The following problem is from "Probability and Statistics in Engineering - Hines, Montgomery" A potential customer enters an automobile dealership every hour. The probability of a salesperson concluding a transaction is 0.10. She is determined to keep working until she has sold three cars...

I'm working through some problems from Stewart's Calulus, 6ed. and am having some difficulty with certain limit proofs. In particular, there is no definition provided for limits of the form: $$ \lim_{x \to - \infty} f(x) = L $$ One of the exercises is to come up with a formal definition...

Hey guys, Not claiming to be an expert on numerical methods here but I am doing some digital integration using simpson's rule that takes 10 samples a second to provide me with the "approximate" integral for that time period. Right now I am currently taking the magnitude of the value I...

Homework Statement For the negative binomial distribution, with r known, describe the natural parameter space Homework Equations the pmf for the negative binomial distribution with parameters r and p can be 1) P(X=x|r,p)= \binom {x-1}{r-1}p^{r}(1-p)^{x-r} where x=r,r+1,... , or 2)...

Homework Statement If I have a electric source charge, does that mean that electric potential increases as r increases (because it gets increasingly less negative as you go farther from the source charge) as opposed to a positive charge in which potential energy would increase as r...

Homework Statement Why do negative charges spontaneously accelerate? The book I am studying from asked me to verify this statement: Negative charges spontaneously accelerate and increase in kinetic energy when they move toward a point of higher potential. I don't understand why...