Relationship Definition and 986 Threads

Since the capacity of an air conditioner is a function of outside air temperature, does it follow that greater efficiency will be achieved by putting the condenser under shade rather than out in the open or on a hot roof? Or does the casing of the unit provide adequate shading to make this...

Since I was 8 years old, I thought I would not have much trouble in making friends and maintaining social relationships with others if I am always honest and kind to everyone. However, as I get older, I realized that being honest and kind will not always guarantee an impeccable social...

hey! Pressure and Volume are inversely proportional to each other When you decrease the volume, the pressure increases. However, when you increase the pressure, it seems to me that the gas molecules want to spread out more and the volume would increase, but boyle's law says that it should...

Hi, I was considering the notion of studying both physics and chemistry, but am reluctant to decide definitively so. I am wondering if anyone knows if there is a relationship between the two, in that they compliment each other, because I plan on doing research in the field of physics. Does...

My girlfriend is re-learning geometry. She has noticed that the sum of the angles of a triangle is equal to the measure of a straight angle and half the measure of a full revolution. She wants me to ask if there is any special relationship between a triangle and a straight angle or between a...

Observations show that the current density of the Universe is close to the critical density: rho = 3 H_0^2 / 8 Pi G Assuming a spherical observable Universe of constant density, together with the relation c = H_0 * R, one can rearrange the above equation to give the relation: G * M / R...

Hi, This is a general question rather than an explicit question, so apologies for not using the template. I'm a bit confused by the relationship between frequency and data rate in a communications system and wondered if someone could help clarify please. Say I want to achieve a data...

Hi, I have a terrible time when solving Inclined Plane problems when it comes to dividing the weight component into two. I can't see why, to find the perpendicular component I do the cos Theta of the weight and the parallel component I do the sin Theta of the weight. Can anyone, (maybe on...

Homework Statement On book 'Switching power supplies A to Z' page 73 at the bottom, (please kindly proceed to the link below for that page) http://books.google.com/books?id=cuyyQ3N_8hIC&lpg=PP1&dq=switching%20power%20supply&pg=PA73#v=onepage&q=switching%20power%20supply&f=true It stated...

I have been told that the hydrogen ion concentration of an acid in solution depends on temperature. What exactly is this relationship? Is there a formal equation that relates [H+] and temperature, as well as any other physical variables that may have an effect?

Hello everyone, In Fermi Liquid Theory, I'm trying to understand what the relationship is between the Green's function and the average occupancy of levels. In my lecture they gave the relation \left\langle n_k \right\rangle = G(k,\tau\rightarrow 0^+) Anyone know where this comes from...

i was wondering if there is a relationship between mass and temperature that would allow me to calculate the surface temperature of a blue super giant of 24 solar masses? or do i simply need more information to do this

i've always wondered this...

Hi, All: Given a simplectic vector space (V,w), i.e., V is an n-dim. Vector Space ( n finite) and w is a symplectic form, i.e., a bilinear, antisymmetric totally isotropic and non-degenerate form, the simplectic groupSp(2n) of V is the (sub)group of GL(V) that...

So I'm a physics student, obviously I don't believe in God or religion, and I can be pretty hostile towards it at times. I recently met a girl who I'm pretty into, but she's deeply christian. I plan on "telling her how I feel" tomorrow, but I'm just wondering... do you think a lasting...

I know the L/T^2 relationship of a simple pendulum gives a constant- g/(2pi)^2. Could anyone please show me how it is derived? Thanks in advance.

Why do we associate the energy eigenstates with the "wavefunction" and "position"? This is something that has bothered me for a long time but that I never got around to asking. I suspect I'll feel like an idiot for not knowing this but anyway... One of the first things I was introduced to...

Howdy ya'll, a relatively simple question, A circular bar 20mm in diameter and 1m long is subjected to an axial load of 50kN. Determine: (i) The normal stress. (ii) The normal strain. (iii) The elongation. Assume the material is steel with an Elastic Modulus of 200GPa. ok so i...

Homework Statement A square is divided into smaller n^2 smaller squares with corners (i,j) Show that for every whole value of k, k= (i+1) + (n+1)*j and this is specific for every choice of i and j.Homework Equations The Attempt at a Solution i see what i have to prove, but i don't know how to...

I'm using Real Mathematical Analysis by Pugh to supplement my analysis class, and the book has been clear thus far, but I've been stuck for days on a concept I've had a hard time understanding. Just for reference, here is how a homeomorphism is defined: And here is how connectedness is...

I am working on a 3D crane system, the system has three dc motors for y, x and z axis, and i control them with a PWM signal. i need to find the relationship between pwm and torque or torque and duty. could someone help me, thanks

Homework Statement consider z = f(x,y) where x= r cos \theta and y = r sin \theta by reartranging the question, obtain the inverse relationship r(x,y) and \theta (x,y) and show that: \deltar / \deltax = cos \theta, \deltar / \deltay = sin \theta \delta\theta / \deltax = -1/r sin\theta...

In an experiment, a ruler is connected to the table and some weights are bounded to one end of the ruler. The ruler is then flicked and the time taken per oscillation is measured. I have plotted a graph with the data I have collected, with the mass on the y-axis and time on x-axis. The graph...

Homework Statement Assume that a planet just like Earth is orbiting the bright star vega at a distance of 1AU. The mass of vega is twice that of the sun. a. How fast is the Earth like planet traveling around vega? b. How long will it take to complete one orbit around vega...

Homework Statement A copper coil has a resistance of 0.541 Ω at room temperature. What is its resistance when it is cooled to -131.3 °C? Homework Equations Ri=New resistance R0=initial resistance a=alpha Ri=R0+R0(a(temp change)) temp change is positive when it goes up alpha...

Could anyone please tell me how the acceleration of an object in a fluid varies with its velocity.

In class it was explained that at half way between a given distance Potential energy(PE) lost equals the Kinetic energy(KE) gained. OR PE Lost = KE Gained at 1/2 the distance. But when i do the math for it, it does not work out. What am i missing, i understand the concept but i can't prove...

1. I have to find out the relationship between tension and resonant frequency in a length of rubber, using stationary waves. 2. I know there is an equation for the resonant frequency in a length of string, given as f= 1/2L * sqrt T/μ . I am however imagining that as this is a rubber band...

This is why I'm avoiding pure math --- axioms. There's no such equivalent thing in science as an axiom. It leaves pure math too open, almost like a programming language. Probably not a good idea for me to go into pure math if I don't understand any of the axioms, anyway; and, anyway, 1) the...

Hi, I was wondering what is the relationship between 'diameter size' and the strength to flex a hollow tube... is it linear or non-linear? I'm measuring the flexural load of different hollow tubes (with different diameter size) and looking for a way to normalize the the flexural load data...

Homework Statement If you double the distance between to masses, the gravitational force between them would:____ If you triple the distance between two masses, the gravitational force between them would be _______ the original force If you Halve the distance between two masses the...

I am a piano teacher with some very cool, science-minded students. Usually we stick to basic acoustics, and mechanics in terms of piano technique, but yesterday one of them took things in an interesting new direction. . . he described to me how, when he closes his eyes and listens to the music...

What is the Relationship between Kepler's law and universal gravitation law? (IT HAS SOMETHING TO DO WITH THE CENTRE OF MASS)I know this; Newton's Law of Universal Gravitation F=mGM/r^2 derived Keplers Third Law r^3/t^2= constant: mGM/r^2 = mv^2/r gives GM/ (2pi)^2 = r^3/t^2. Read more...

What is the relationship between harmonics and wave amplitude in a resonant object? Lets say we have an object which has a natural resonant frequency of 50hz. we connect that object to a signal generator set at 50hz and note the amplitude of the oscillations the object. Next we go up one...

Homework Statement Polynomials p(x) and q(x) are given by relationship q(x)=p(x)(x5-2x+2). a) If x-2 is a factor of p(x)-5 , find the remainder when q(x) is divided by x-2. b) If p(x) is of the form x2+ax+b and x-1 is a factor of p(x)-5, find the values of a and b. Homework...

The g-factor of an electron (-2.002) added to the g-factor of a proton (-3.826) approximately equals the negative g-factor value of a proton (5.585). Ge + Gn = -5.828 Is there any significance in this?

Since the permeability of free space is a measure of how free space resists a magnetic field, shouldn't it be inversely proportional like the permittivity of free space with respect to the electric field? B = μqrsin / 4πr^2 E = q / 4πεr^2

I was thinking about the 1/2 in KE = 1/2*m*v2 I thought about how strange it was, and then I realized that as a function on velocity (v), kinetic energy is the antiderivative function of momentum. However, I am very confused as to what that implies. My question is very vague, but what...

A^closure = X\(X\A)^interior I am REALLY bad at proofs. I never know where to start. I only have the definitions of closure and interior. I feel like they threw us in the deep end I've written like 3pages, but mostly just pictures. interior: a is an element of A^int iff there exists r>0...

I am having a hard time understanding this concept... I understand Rectilinear motion consists of a line and Angular Motion is of a Angle. But I can't seem to understand how to use this for problem solving. I have two examples here that I will give and I have the answers but I can't seem...

Hi Physics Forums, I understand that I usually need to show that I've attempted a question in order to get feedback, but I have absolutely no idea how to approach this one Calculus Log question. Base = 10 log (2) = 0.301103, log (3) = 0.47715 a.) Find log base 6 (5) b.) Estimate...

how F-number of a lens and spherical aberration are related?

I know that, for time-independent potentials, we have E=sum (Vi*partial dL/dVi) - L What if one or more of the potentials are time-dependent? Is the relationship between energy and the lagrangian then "total dE/dt = - partial dL/dt "?

Hello, First time posting here as I havn't been able to find a suitable answer to my question to help me understand some issues I am having with DC motors. I am trying to calculate the maximum speed and acceleration of a dc motor being driven by a current source with a known inertia. I...

Would you say voltage drop across a resistor is directly proportional to the resistance. I am trying to understand the relationship between voltage and resistance. Thanks.

Hello, I'm quite new to the concepts of quantum theory. So as such I have an interesting quandary. Keep in mind that I don't have as much back ground in study of physics as the lot of you but I will try my best to explain my dilemma. Given 1)Both the electron and nucleus have a charge and...

Is it possible to have a good relationship when the two people don't basically agree on politics? Granted, some people can agree that it's good to differ but what if they differ in the most fundamental beliefs about politics? E.g. what if one person really likes a certain politician, party, or...

Hi, Could you clarify the relationship between proofs that use ≤ and those that use <? For example, if it's already proven that "abs(b) ≤ a if and only if -a≤ b≤a" can we say this implies that "abs(b) < a if and only if -a< b<a"? It seems that since the first statement holds for all abs(b)...

I have been "googling" to find the relationship between the above, and the answer has mostly been a resounding "NO". Maybe my question is not "CFM" vs "PSI", but that is the only way I know how to descibe my question. I will explain the scenario: I have air flowing at a constant speed...

Homework Statement Calculate Speed (v sub mp) and rotation speed (\omega Homework Equations (v sub mp) =Sq rt (2kT/m) <V>= 2/ (sqr rt pi )(V sub mp) Vrms = sq rt (3/2) X V sub mp How do I relatate these to rotational speed? The Attempt at a Solution Yo mamma The numbers came...