Change Definition and 1000 Threads

I am encountering this kind of problem in physics. The problem is like this: Some quantity ##A## is identified as a potential field of a ##U(1)## bundle on a space ##M## (usually a torus), because it transforms like this ##{A_j}(p) = {A_i}(p) + id\Lambda (p)## in the intersection between...

During a thermodynamic process, the state variables of an ideal gas, measured in kPa, m3, and oC, varied in the following way: P2 = 2P1 V2 = 3V1 T2 = 8T1 What is the temperature increase of the gas, T2 −T1 ? I've been given an answer of 4780 and I'm not sure how to get there?

So I understand that scientists have been able to slow light to extremely low speeds using Bose-Einstein Condensates and even without them (https://physics.aps.org/story/v3/st37) and if I understand this correctly they slow light the same way water or air does; atoms absorb the photons and...

Hi there, I am doing a physics assignment. I had to use a program called tracker to simulate the movement of a puck. So I just need some help to see if anyone can figure out what I've done wrong as something isn't making much sense. Let's jump right into it. When the puck moves down and hits...

I'm looking into chemical battery that use the molecular tension in chemicals like white phosphorus to store heat energy.But finding a way to slow and defuse the heat and flammability of phosphorus with tungsten and sliver is easy. But rebuilding the molecular tension is harder.

Why the tangential velocity of a particle increase if there are no external torque acting on it and its angular momentum is conserved? I know that L = I.ω (angular momentum equals moment of inertia times angular velocity) and v = ω.r (tangential velocity equals angular velocity times the...

Suppose at the instant a gravitational wave passes through an interferometer, one of the interferometer's arm get stretched by 1%. Would the wavelength of the photon traveling in the arm also get stretched by 1%? If so, then would the frequency of the photon remain the same and hence increasing...

Why is it that the flux linkage does not change instantaneously ? is it some property of magnetic fields?

I haven't touched a physics textbook in a while and need help with something fairly simple. I am staring straight down on a rectangular prism that is tilted on one axis to a known angle, theta. I have a measurement of a vector length in this orientation. I would like to know how much that length...

Hey! :o Let $D$ be the space in the first quadrant of the $xy$-plane that is defined by the inequality $x^{\frac{3}{2}}+y^{\frac{3}{2}} \leq \alpha^{\frac{3}{2}}$ with $\alpha>0$. I want to transform $\iint_D f(x,y) dx dy$ to an integral on the triangle $E$ of the $uv$-plane that is defined by...

Homework Statement A satellite is in a circular orbit passing over the North and South geographical poles as it orbits the Earth. It has a mass of 2200kg and its orbit height is 870km above the Earth's surface. What is the change in momentum of the satellite from when it passes over the...

Homework Statement Two systems that have the same heat capacity Cv but different initial temperatures T1 and T2 (with T2 > T1) are placed in thermal contact with each other for a brief time, so that some heat flows but the temperature of neither system changes appreciably. Show that there is a...

Hi, I am confused about which to choose between computational physics and data science. Actually I am a computer science undergraduate and I have 4 years of experience in data mining. I discovered my interest in physics, so I planned to do a graduate degree with the focus of physics. But the...

Homework Statement Homework EquationsThe Attempt at a Solution I didn't understand the last part. At eqbm. ##\Delta S = 0##. This means that the RHS of the eqnn. 14.25 is 0. This doesn't mean that the following eqns. must hold true. ##(\frac 1 T_1 - \frac 1 T_2) =0,.............(1) \\...

Hi, In a demostration i found a change in order i can't understand. how can the differential pass in the beginning part? the only thing I'm sure is that "v" and "dr" are parallel

I was performing XRD earlier, and I came across this odd occurrence in the powders that were being inspected - After it was performed, the crystalline powder I had been testing had gone off color into this yellowish appearance (Originally was white). Upon disturbance, the powder become white...

Hey guys, A quick question on a career change... Is it worth pursuing a career in scientific research later in life? The reason I ask this is that even though it's illegal I still believe ageism is a factor for us the older lot to not be favoured over the younger crowd. I have had direct...

It is reported that TiO2 thin surface amorphous layer left after acid-etching with hot HCl-H2SO4 solution slowly changes from the original flat surface to a layer rich in nano-scale features (granules attached to the surface) of 20 ~ 30 nm in size. You can see these nano-features in the picture...

Homework Statement The motion of a particle is described in standard planepolar coordinates. Derive an expression for each of ##\frac{d\hat{r}}{d\theta}## and ##\frac{d\hat{\theta}}{d\theta}##, each in terms of one or both of ##\hat{r}## and ##\hat{\theta}## as necessary. Derive both results...

I had no idea where to place this, so my apologies if I chose the wrong topic. Hi, For a certain application I need to heat very small (< 0.2 mm^3) quantities of ethanol until it vaporizes (78 °C) and then cool it down again until it's a liquid again. The hard part is that this all needs to...

$\tiny{232.15.4.46}$ $\textsf{Change the order then evaluate}$ \begin{align*}\displaystyle I&=\int_{0}^{1}\int_{0}^{2}\int_{2y}^{4} \frac{5\cos(x^2)}{2z} \, dx \, dy \, dz \end{align*} ok I presume the change that should be made is... altho I don't know what represents x or y...

Homework Statement If my car was moving to the right then I changed direction of motion to down, and the speed is constant and =5m\s, how to calculate acceleration Homework Equations Δv=vf-vi The Attempt at a Solution Make vectors addtion and use pythagorean theorem formula, so change in v...

Hello, This is a little long but I promise it won't take that long to read and I want to tell my whole story. I have posted on here before in the past, but those posts are now conflicting and totally irrelevant. I've gone through a rough patch in my life where I couldn't decide what I want to...

If I'm driving a car and I have changed my dierction of motion without changing the speed, in this case how to calculate the acceleration of the car in a particular time? I'm not talking about circular motion.

For my research I am trying to study the temperature change of a warm fluid (air) flowing over a cold surface, but I have not studied fluid mechanics. Does anyone know of an equation that can be used to analyze this problem? To give some reference, the hot air is 49 Celsius and the cold air is...

Homework Statement A mixture of hydrogen, carbon monoxide and carbon dioxide is being fed to a compressor at 2.0 bar and 25 C. The overall flow rate is 17.47 SCMS and its composition is 73.5 mol% H2, 13.7 mol% CO and the balance CO2 The compressor operates adiabatically and reversibly with a...

Hello, I just did a practice physics problem that asked if an object with constant acceleration can change direction twice. The answer was no. What if you had an object attached to a string spinning at constant velocity. Is the tangential acceleration constant?

Dear All, This is my first question to the forum. "Assume there is a + dc voltage across a inductor. So current will continue to increase. Now if the current through the inductor is forced to stop using some means ( eg. Current was flowing in inductor through a ON switch and then switch turns...

Homework Statement The radius of a circle increases from 3 to 3.01 cm. Find the approximate change in its perimeter. Here's a link to the actual question, in case you need the answer for 6(a) to solve 6(b) http://imgur.com/a/nQt6M Homework Equations Perimeter of circle = 2πr Area of circle =...

Apologies in advance. I am on page 1 of physics. My question is simple. Can I replace the word 'energy' with the word 'change' . Is energy simply 'change that has been quantified'. Take 2 cases. Case 1 -A boy bounces a ball and the ball changes shape and bounces through a window breaking...

Using a green laser instead of a red laser seems to change the way the ray changes during refraction. Why is that so?

Homework Statement Hi everyone. We were discussing conservation of angular momentum as a consequence of rotational invariance in class. There was one point where we needed to compute the change in a vector A when the coordinate frame is rotated by angle Δ(Φ). Homework Equations The teacher...

Recently I was searching the internet and books for the connection between conservation of angular momentum and conservation of rotational energy and found nothing. Let's say an ice skater rotates and draws the arms in - the rotation speeds up. The rotational energy must increase because the...

I know that in a para magnetic material the magnetization increase on cooling. What will be the same effect on a diamagnetic material,considering the fact that Curies law doesn't hold good on diamagnetic materials.

Good afternoon all, For those of you that teach physics, if an object has an initial velocity of - 5m/s and a final velocity of -20 m/s, do you consider the velocity to be increasing or decreasing in this case? I view this to be strictly defined mathematically, that is that the acceleration is...

I can't understand why a gas passing through a porous plug experiences change in its pressure and why does the cooling or heating process depends upon the initial temperature

$\tiny{hcc8.11}$ $\textsf{Find product $(1+3i)(2-2i)$}\\$ $8 + 4i$ $\textsf{Then change each to complex form and find product. with DeMoine's Theorem}$ $\textit{ok looked at an example but ??}

If I do the x-axis rotation for a solenoid, how will the magnetic field change? Would it also rotate along x axis?

Homework Statement I have attached the problem. A 14,000 kg tractor traveling north at 21 km/h turns west and travels 26 km/h. Calculate the change in the tractor's a. kinetic energy b. linear momentum (magnitude AND direction) Homework Equations [/B] delta KE = (1/2)mv^2 - (1/2)mvi^2...

Homework Statement I'm trying to digest the concept of change in potential energy being set equal to a change in kinetic energy. Does this relationship always hold? Please see below for more details. Homework Equations PE = mgh KE = .5mv^2 W = ΔKE = -ΔPE W = f*d The Attempt at a Solution...

Hey guys, if I consider a Bernoulli-Beam with a constant jump in cross- section as shown below Then I get the two differential equations for the bending mentioned above. Let us now assume that a traveling wave from the left w_incident = C*cos(k_1*x - ωt) arrives at t = 0 at the jump of...

Homework Statement Without introducing any coordinates or basis vectors, show that, when a charged particle interacts with electric and magnetic fields, its energy changes at a rate $$\frac{dE}{dt}=\vec{v}\cdot \vec{E} $$ Homework Equations ##E_{kin} + E_{pot}= En =## const (1)...

https://www.youtube.com/channel/UC4mLlRa_dezwvytudo9s1sw I don't know if watching it on PF has the same effect as watching it on youtube, so just to be sure, watch it on youtube to give him the support he deserves. And don't skip the commercial - he get's paid for that! Commentary...

Yes, this is kind of a weird question to make, but I haven't found anyone discussing it so I decided to ask it myself. The question: Is it possible to change the pitch of a voice up two tones (for example), in order to create a harmonizer that has no electronics involved? The idea and where it...

My question is, take Mars, say, and install a huge rocket engine on the ground pointing out the planet (obviously) and in the opposite direction of its velocity, so that if it is turned on, the planet is slowed. The rocket starts to work and Mars is slowed. If the loss of velocity goes little by...

If I have a closed cylinder with a fixed air volume inside and a piston on the open end I need to calculate how much the piston will move as the temperature changes through a range of 100 degrees F? Air volume vs temperature?

Homework Statement Special relativity: A rod traveling with the relativistic velocity of 0.866c moving towards a garage. The length of the rod is L, that of the garage is L/2. From the reference frame of the garage, we find the value of Lorentz factor = 2 we say that rod would fit inside garage...

1. Homework Statement This is my first question and I'll try to stick to the forum rules as much as possible. imgur.com/a/2JyZC Imagine a cylinder filled with air which is uniformly distributed and a piston above it, so the air can expand vertically. Let the system be the air itself, so the...

Homework Statement Homework Equations Equation given in question. The Attempt at a Solution The only thing I could think of was to try changing the y=3x^3 into polar coordinates but I didn't know where to go from there... Could I get some direction to how I should go about this, I'm sort of...