Work Definition and 998 Threads

i wear glasses to correct my out of focus vision. Without glasses everything is slightly out of focus. Quite by accident I looked through a tiny pinhole about the size of a pinprick without my glasses using one eye. To my amazement everything was perfectly sharply in focus. The same with...

I studied the work of a nano generator in quantu mechanics. The generator uses the principle of triboelectrics. How does this work in quantum field theory? I think that the electron (wave packet in the field) is in the atom in a small volume because the nucleus inhibits the propagation of the...

I have found different values depending where is read. I should like have a graphene sheet on copper to be used in a ionizer to generate lots of electrons

Homework Statement Homework Equations fd cos theta The Attempt at a Solution Finding the work done. Please anybody help me[/B]

Why isn't it called deltaP *delta V work? Or deltaP*V work? Does the expression mean that P is constant while V changes and also what is an example of that? thanks for any help

I am trying to solve problems where I calculate work do to force along paths in cylindrical and spherical coordinates. I can do almost by rote the problems in Cartesian: given a force ##\vec{F} = f(x,y,z)\hat{x} + g(x,y,z)\hat{y}+ h(x,y,z)\hat{z}## I can parametricize my some curve ##\gamma...

Homework Statement Movers must push a piano onto a truck, the bed of which is a height 1.35 m above the ground. To do this they will use a frictionless ramp. If the piano has a mass of 1806.0 kg and the movers push it up the slope at a constant velocity, how much work do they need to do on it...

<Moderator's note: Moved from a technical forum and thus no template.> Hi all, I have attempted this question but have a few queries on how transformers work, and what the dot notation represents. (a) The flux would be clockwise around the iron core. (b) This is the question where it gets a...

Homework Statement (Please check the attached image) 2. Homework Equations The Attempt at a Solution Those are my answers. I thought the magnitude of the applied force would be bigger because that would be responsible of keeping the block on that spot without having it pulled back by the...

Homework Statement I don’t understand why this would relate to cosine and not sine, if gravity is often assiciated in the up and down part of a free body diagram. Homework Equations Wg=mgdcos(theta)[/B]The Attempt at a Solution Is it because it would depend on your reference frame?

Zero gravity. We can hear about the zero gravity chamber , zero-g flights on aeroplane and lots of other stuffs about zero gravity on earth. How does it actually works? Can it be possible for us to make it?

Homework Statement An object with mass 100 kg moved in outer space. When it was at location < 9,-24,-4 > its speed was 3.5 m/s. A single constant force < 250,400,-170 > N acted on the object while the object moved from location < 9,-24,-4 > m to location < 15,-17,-8 > m. Then a different single...

Homework Statement you push a box out of a carpeted room and along a hallway with a waxed linoleum floor. While pushing the crate 2 m out of the room you exert a force of 34 N; while pushing it 6 m along the hallway you exert a force of 13 N. To slow it down you exert a force of 40 N through a...

<edit: moved to homework. No template in the post.> An ice maker inputs liquid water at 25 degrees C and outputs ice at -5 degrees C. Assume there is 1 kg of water and the volume does not change. Cp liquid 4.18 kJ/kg-K Cp solid 2.11 kJ/kg-K ∆H fusion 334 kJ/kg I need to...

Homework Statement A force varies with time according to the expression F=aΔt, where a = 2.0 N/s. From this information, can you determine the work done on a particle that experienced this force over a displacement of 0.50 m? Homework Equations W = F*d Vf = Vo + aΔt F = ma The Attempt at a...

Homework Statement Derive an expression for the change of temperature of a solid material that is compressed adiabatically and reversible in terms of physical quantities. (The second part of this problem is: The pressure on a block of iron is increased by 1000 atm adiabatically and...

I am a student at a trade school, majoring in HVAC. My electricity for HVAC textbook has a chapter on electric meters. However, my textbook does a poor job of explaining how a digital ammeter works. My textbook has the following description of how digital ammeters work: "To make meters...

how can we use Cp.dT to evaluate compressor work even when one side (inlet side) is having different pressure than other side (outlet side). Cp should be used for constant pressure!

When I use the air conditioner in my Toyota Camry, and I move the temperature control towards warmer: Does it make the AC cycle on/off thus saving fuel? Does it mix warm air with the cold, thus saving no fuel? I couldn't find an answer to this on Toyota forums.

I’m having trouble understanding the relationship between how work is both a dot product and integral. I know that work equals F • D and also the integral of F(x): the area under the curve of F and D. However, let’s say that I have a force vector <3,4> and a displacement vector of <3,0>. The...

Hi, today in lecture, we discussed the work done on inserting a dielectric between a capacitor. Two cases of this example: One case, where the battery is disconnected so that the charge stays constant. Other case where the battery stays connected so voltage is constant. I am confused on...

I was reading my latest Reader's Digest in which appears an article about ultraviolet photography. The article explains that this kind of photography utilises a technique known as ultraviolet induced visible fluorescence. The article says that the technique allows flowers to reveal spectacular...

if I apply a force constant F=100N en ##y## direction to a body of mass 2kg, it is elevated 3m and I know that the force of gravity is in ##y## direction too. What is the work that I did? I think: ##W_{me}=(F_{me}-F_{g})\times 3## it is correct? and the work made by gravity is "0".

Hi - I'm looking for some help with the solution of this problem "A 1 kg block situated on a rough incline is connected to a spring with spring constant 100 Nm-1 as shown in Figure. The block is released from rest with the spring in the unstretched position. The block moves 10 cm down the...

the problems/challenges that you have to face daily are mostly related to code issues with the physics itself? Is there room to improve our knowledge of fundamental physics while working on it? Do you enjoy doing it? why? I'm asking this because I'm considering working on numerical relativity...

Hi - Question: A person trying to lose weight (dieter) lifts a 10 kg mass, one thousand times, to a height of 0.5 m each time. Assume that the potential energy lost each time she lowers the mass is dissipated. (a) How much work does she do against the gravitational force ? (b) Fat supplies 3.8...

Homework Statement Taking my Electricity and Magnitism course right now and we are in the section in the book of the electric potential. I have some basic questions regarding work and potential energy. Lets say we are holding a ball 10m above the ground and release it. I am defining the ground...

I'm trying to solve a problem where a perfect ideal gas is entering an initially evacuated rigid vessel. The input pressure and temperature are Pi and Ti which are constant. The incoming mass Mi is an arbitrary function of time. When i solve this, i get the temperature inside the container as...

Homework Statement The force on a particle is directed along an x axis and given by F = F0(x/x0 - 1) where x is in meters and F is in Newtons. If F0 = 1.5 N and x0 = 4.9 m, find the work done by the force in moving the particle from x = 0 to x = 2x0 m. Homework Equations F = force, w = work, x...

Homework Statement I have a hipotetic rocket that have a power of 3000 watt, however its position don't change because the effect of a gravity of 10m/s^2 do the rocket remains like it would be resting. I need to determine the mass of the rocket. In a similar problem I have a rocket also in an...

http://www.animations.physics.unsw.edu.au/jw/rotation.htm#rolling I have set up an apparatus similar to what the above link says (the first bit about brass object with shaft). So basically, the shaft is in contact when the brass is first rolling, then it suddenly accelerates when the edge of...

Homework Statement There is an insulated internal combustion engine fueled by one mole of octane. It operates at a constant pressure of 5.0 bar. The initial temperature is 200°C. Calculate the heat exchanged with the surroundings, the Δh for the gas, the final temperature, the work performed...

I don't know whether this question is suited to this forum specifically, but since it deals with electronics, I am putting it here. We have an old air-conditioner, bought in 2007. As you can understand, it is one of the old models running on R22 gas and it switches off the compressor when the...

Hello all. In his books on classical mechanics, David Morin claims that when computing the work W = F Δx done by a contact force that don’t involve any slipping, we can equivalently say that Δx is the displacement of the thing that is applying the force. Later, when analysing a wheel rolling...

Homework Statement In a Franck-Hertz experiment carried out with potassium vapour, it is found that the current falls off rapidly at an applied voltage of 1.62V. Calculate the wavelength of the expected spectral line in the emission spectrum of potassium when this voltage is reached. Homework...

I have scoliosis (congenital, unknown cause), and according to my physiotherapist and my otorhinolaryngologist, the problem with my case is orthopedic. Thursday I asked my vestibular physiotherapist some article that explained my situation. I eat something or drink some juice (the vertigo goes...

So I recently picked up 40 of 10.525 GHz Microwave RADAR transmitters: I opened up one out of curiosity and had something like this (image attached) . I noticed some parts of the PCB aren't even connected to anything. How do the different shapes and sizes of the PCB interact with each-other...

Homework Statement The question is: One kilogram of a gas with a molecular weight of 35 is contained in a balloon. The initial conditions are 27 C and 0.025 m^3. The gas is slowly heated isothermally until the final volume is 0.05m^3. The atmospheric conditions are 100 kPa and 27 C. The p-v-T...

Is there any way to harness the hydrostatic pressure gradient to generate energy? The pressure at the surface of an ocean is atmospheric pressure.As we descend down the ocean, the pressure increases .After a point, the pressure will be very high.Why can't we use this pressure difference to do work?

If giving the average speed weight and distance traveled is it possible to work out when the object stopped accelerating

Does an ordinary pipe fitting, such as an elbow work when screwed onto a male compression fitting"? - or won't the connection seal properly? The situation shown in the photo: I need to replace a 1/4 inch copper tube water supply line (to the ice maker on a refrigerator) with a 1/4 inch braided...

All, I started this strange little thought experiment this morning, but I'm not quite sure what I'm missing. Here's the problem I solved (this is not homework, BTW): Find the speed at which a super hero (mass=76.0 kg) must fly into a train (mass = 19,537 kg) traveling at 35 m/s to stop it ...

Homework Statement [/B] An ideal gas is compressed to the same volume from the same initial state for both an adiabatic and an isothermal process. In which case will more work be done ? 2. Homework Equations ##dU=dQ - dW ## ##W=\int P\,dV ##(For isothermal) ##W=nc_vdT##...

Homework Statement The objects are set free from the scenario shown in the attached image. Their masses have been given and they are under the effect of gravity. The length of the string has been shown in the figure. If the two blocks cross each other, then we need to determine the minimum...

Homework Statement Hi all, could someone give my working a quick skim to see if it checks out? Many thanks in advance. Suppose that 5 cards are dealt from a 52-card deck. What is the probability of drawing at least two kings given that there is at least one king?Homework Equations The Attempt...

When an ideal gas,in a piston kind of system and whose equilibrium state is mentioned, is allowed to expand (piston is allowed to move and not gas leaking )against a constant external pressure very quickly, then, is the work done by gas zero or not zero ? The argument for work being zero is...

I know that I'm rushing too much but I wanted to see if I can calculate the work of a pendulum that does oscillation with a similar way you calculate the work of a spring. Consider the following free body diagram: Things i noticed: 1) The position is changing both in x and y-axis while the...

Homework Statement A spring has been attached to an object which is kept on the ground. The spring is initially in its natural length: 'l' when a force 'F' is applied on it. The force 'F' slowly pulls the object so it does not attain any acceleration. There's a point 'P' on the line which is...

Hello, i would like to ask You a question about difference in results between Euler-Bernoulli method of analysis of stress in short slender beam and 3D FEA method mentioned in ansys aim tutorial here: https://confluence.cornell.edu/pages/viewpage.action?pageId=33636829 The problem looks like...

Hello, I've made a version of Kelvin's water dropper for a school project, but it is not charging up. I've made the supports with PVC and the base with plywood. The water collectors are placed on Styrofoam blocks and the water flows through holes made in 2 plastic bottles. The inducers and...