Work Definition and 999 Threads

The answer is .32m. I set the elastic potential energy as equal to the work, but at first I put the force in the work equation as (F elastic - F kinetic friction) times distance and rearranged. 1/2kx^2 = (kx-Ff) d (0.5) (22) (0.035)^2 = (22 x 0.035-0.042) d 0.013475= 0.728 d 0.013475/0.728 = d...

I was reading a paper by J.M.C Montanus which was published in <low quality journal reference removed> in which he claims under AEST the new gravitational dynamics and electrodynamics are reformulated in close correspondence with classical physics, and subsequently leads to the correct...

photo below... Is it possible to make a machine that would take more heat from the hot reservoir to do work than what would hot reservoir give to the cold reservoir(heat)? Apparently, it's impossible because it violates 1st law of thermodynamics. the thickness of the arrows symbolizes the...

I understand that some numbers cannot be represented in floating point but I don't understand why the way we obtain those numbers matters. In python, if I type print(0.1) or print(1/10) I get 0.1 but if I type print(0.3-0.2) I get 0.09999999... Why the difference?

What force causes the surface to move to the left? Can I say that it's due to the force component of the weight along the vertical force of the surface?

(picture of diagram below)So the task goes like this: gas is ideal. Process 3->1 s adiabatic and in process 1->2 work done is 1200J. Fill the table. I don't know how to calculate work done in an adiabatic process because p2 and V2 are not given and I don't know gama(Cp/Cv). I know that deltaU...

The solution said that Average power= net change in energy/time, but why is that true? If you have a different way of solving it, it would be helpful too

Can anyone tell me if my answer is wrong ?!

I need a method to accelerate a ball bearing down a pair of wire tracks, and to generate a consistent amount of force on every activation. Please critique my tentative design: I want to use an inductive coil activated by a proximity sensor to generate a transient EM field to accelerate the ball...

I used the regular way of solving problems with pulleys. I tried to find the tension forces, which must be the same in the rope, but I get it wrong

So, from what I remember, W=F*D*cos (θ). If I'm lifting, θ=90° and so, the cos = 0. So is the work just 0? Why? I still moved the object through a distance, which is the usual non-mathematical definition of Work.

As we know, when we turn on a tub/shower combo the water initially starts to flow out the tub faucet. When the lever is raised, the water is diverted to the upper shower head. How does this work? I have learned that the tub faucet lever merely blocks off the water from coming out of the...

In defining the heat capacity of a subatance as the constant relating change in temperature to change in heat, is it assumed that the system does no work? Does it really say (heat capacity is the constant relating heat change to temperature change when the system does no work)?

Hello, Suppose I have a spherical hole in a elastic infinite space. I apply a time-dependent pressure to the inner surface of the spherical hole. I know p = f(t). If I only consider this as an elastic problem, no failure happened, how can I calculate the work done by p during the time from 0...

I am post-processing a simulation. A spherical is meshed by many little triangles. A time-dependent pressure (p=10*t) is equally applied to the inner surface of a spherical in the normal direction all the time. After t1=0.1s, the spherical is broken, and each little triangle is disconnected...

I'm wondering what's the difference between work done on quasi-static and non quasi-static expansion. In a quasi-static process, the gas inside the system must do a work to "extend". However, in a non quasi-static process, where the gas inside the system doesn't move fast enough to "push" the...

Hi all, I just read this article about how electrical transformers work and have some questions. https://www.dfliq.net/blog/the-basics-of-electrical-transformers/#:~:text=The%20three%20important%20components%20of,magnetic%20flux%20is%20initially%20produced. i). What exactly is magnetic...

Suppose I'm considering a system of N particles that are constrained in their possible motions and so there are less that 3N generalized coordinates. Suppose now I perform a virtual displacement on one particle, which due to some constraints might force some other particles to more virtually...

In its path to the exit it is, disassociated, and still trapped in this enclosure with only a path forward. So now it is in two forms of gas, so the pressure of the expansion in the enclosed enclosure and now traveling at high speed towards the exit, and most likely ionized. It is then subjected...

In this 2D figure below, I can place: a motor at O a motor at J gravity on each link I can use Hamilton's principle, modified to the principle of virtual work and I can compute the motion of the linkage system. I do not have to account for these force FOUR forces (in this planar problem)...

Hi, everyone! There are a lot of work energy conservation laws and I get confused which one of them summarizes all of them. Which one I should keep with me and rest should be easy to derive on spot ? 1. ##\Delta E_{mec}=0## 2. ##\Delta E_{mec}=W_{ext}## 3.##\Delta E_{mec} + \Delta...

Hi guys, I'm about to start my degree in a few months and I know what field I want to major in but I don't know what track I should take. In the future I want to work with rockets and spacecraft engines, I want to help develop the new generation. Correct me if I'm wrong but it's called a...

This brief worked example from a textbook section on the method of images is confusing me. Specifically I am confused about the vector α in the integral on the last line. When α (or θ) is an angle, I've only ever seen the vector quantity α (or θ) as a polar vector in the plane. But here...

I did a prac where we tried to calculate the rydberg constant for hydrogen. We had a hydrogen lamp and we used a spectrometer that was hooked up to a photomultiplier tube to detect the wavelengths of light corresponding to the balmer series. In one section I need to write up a brief summary of...

Ubuntu 22.04.1 has been released recently, and the Software Centre shows that my system is ready to upgrade. I want to upgrade, but I am a bit afraid because there is no option to rollback the upgrade. I have a number of applications that are essential and I need them to work properly: MATLAB...

Hello ! I've got a problem understanding what are Lumens and how do I look at lux as well. For example here : It makes 800 Lumens in 1 m^2. Does it mean that in every direction in 1m^2 there are 800 Lumens ? Or when I have a light bult with 800 lumens : Those 800 Lumens in light bult...

I recall that there was an argument from Born expansion showing that exchange of odd spin between equal sign charges generates a repulsive potential, and if the charges are different or the spin is even the potential is attractive. I wonder, how does it work for non abelian gauge theory...

just hypothetical question, First off I am not very knowledgeable in pumps. Let's say you have a pump to pump fluid, i don't think the type matters, self priming as I understand it creates a vacuum with the air in the system to pull the fluid towards the gear pumps. I'm wondering what happens...

What are these sheets with grids and angle references called, that people use on their work tables?

I already know the solution to this, all you do is set the height of the top of the trampoline to 0 and solve for initial velocity so the equation for the conservation of energy $$mgh_0 + \frac{1}{2}mv_0^2 + \frac{1}{2}kx_0^2 = mgh_1 + \frac{1}{2}mv_1^2 + \frac{1}{2}kx_1^2$$ becomes...

Hot air rises due to the candle below. But how does that create a horizontal force, which is needed to produce the rotational torque?

Hello The formula Mgh is commonly accepted as the work done by raising a mass by a distance h, where M is defined as the mass of the object raised. However, is this really the mass, or the weight, simply obtained by weighing the object? If it's the weight, then doesn't the equation...

I tried using the 109 J to convert to seconds but that didn't work. I also looked through the energy equations but nothing worked. I am not sure how to find time.

Hello physics researchers, teachers and enthusiasts. I notice one little thing is confusing me in the derivation of Bernoulli's equation in the article, they write:$$dW = dK + dU$$where dW is the work done to the fluid, dK is the change in kinetic energy of the fluid, and dU is the change in...

Hi! So, I've actually already solved this problem.. for the most part. I have split up the work into two sections, floor 0 to 10, and floor 10 to 15. From floor 0 to 10, I did ## F_{elevator} = w_{pass.} + w_{elev.} ## ## F = (70)(20 (num. of pass.))(9.8) + (800)(9.8) ## ## F_{elev.} = 21560N...

Hi. I'm a high school student interested in applied math, including but not limited to climate modelling, auto differentiation, and simulations. It'd be really nice if I could get some experience in those fields in a structured learning environment, like an internship, with mentors if possible...

A convergent version ( i.e. convergent in the critical strip) of the traditional series for the Riemann Zeta is derived in the video linked at the bottom. It gives the correct numerical values (at least along the critical line, where I tried it out). But although it works numerically, I'm...

Does Ohm’s Law, V = IR work for light bulbs? It appears not to from my simple experiment below. In the figure below, I measured the resistance of a lightbulb and found that resistance to be 2.6 ohms. However, when I connect this lightbulb into the circuit where I measure the voltage across...

I don't understand what I have done wrong in part (c) I have the initial velocity for the second part of the motion and have the final velocity zero and then the net work done is W_mg + W_Fs and the actual answer for x is 2.37m Could I get some help/tips please, thanks in advance. Here is my...

I'm very skeptical of supplements and other products that supposedly boost testosterone and brain health. They are always on TV, and I wonder if they are just snake oil OR if there are any ones that actually do benefit the body. My mother takes Magnesium Glycinate every night to keep her...

Hi, I've heard about the EPR paradox as follows: Leave two entangled particles A and B carried by scientists A' and B', with a pair of incompatible properties (eg spin up/down and left/right) in possible Green/Yellow and Blue/Red states. If one measures Yellow state (eg, particle B in spin up...

During a thermodynamic cycle, an ideal thermal machine absorbs heat Q2 > 0 from a hot source and uses it to perform Work W > 0, giving a cold source a heat Q1 < 0 with an efficiency of 20% . How much is the work done as a function of Q1 ?I have 2 question regarding this problem: 1) Why is Q1 the...

This is a thermodynamics question. A gas absorbs 10 000 J of heat , it releases 3000 J and does 2000 J of work. How much has the internal energy varied? So I did 10 000 - 3000 -2000 = 5000 J so internal energy decreases by 5000 J. But the correct answer is A) it increased by 5000 J . How ?

I'm installing 4 motorized dampers in my basement HVAC, the motor on each unit is 24V drawing 6 watts at 0.25 Amps. I will be powering them from one 24V 40VA transformer. One temperature controller, that uses direct output and has a max output capacity of 10A, will be installed between the power...

Hi there, this question has already been discussed in this forum, however I do not know how to proceed further and if my reasoning is correct. I start by imagining a downard displacement of the 1kg weight. As a consequence of this, block A moves upward and to the right. Also, block B moves...

I am a mechanical engineer and my experience with electrical systems is almost nil. The concept of a simple DC motor explained here was quite interesting, especially the need of a commutator part: And then I checked this DIY simple DC motor here and was confused because there was no...

hi everyone, i need to build a dc motor for my school project. I have used copper wire for the turns (60 turns), wood to build the structure of the armature and commutator. i have used neodymium magnets as my permanent magnets and paper clips as the brushes. I tried using a 9v battery with a...

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The equation I know for adiabatic work is W = P1V1((V1/V2)ϒ-1 - 1))/ϒ-1, but this involves ϒ, but I can use ϒ = Cp/Cv = Cv+R/Cv = 1 + Cv/R, does this seem correct? But I still have a P1