Work Definition and 998 Threads

Hi, this is not an exercise. In some lecture notes the authors states that from elementary EM I should familiar with the fact that the work associated with polarization and magnetization of a material is given by ##\delta W = E dP## and ##\delta W = BdM##. I have to admit that I am super rusty...

<work done a system> a) w=5N*(0.4m)=2J I think this is right, but b) center of mass initial = ((0.5kg)(0.05m)+0.5kg(0.65m))/1kg = 0.35m center of mass final = ((0.5kg)(0.45m)+0.5kg(0.4+0.1+0.3+0.25))/1kg = 0.75m I'm not sure for this one... How can I calculate the displacement of the...

So when explaining the results of quantum double slit experiments that have evolved from the classical wave double slit experiment, popular lecturers of quantum mechanics often show an animation of an electron gun or photon source shooting a lot of particles towards a double slit. The effect is...

i. the threshold frequency; 3.9x10^14hz? it appears the line intersects at 3.9ii. the work function of the surface; 6.626x10^-34x3.9x10^14= 2.58414 × 10^-19J iii. Planck's constant unsure

I noticed that I posted this question on the wrong section previously by accident and I don't know how to delete it... Sorry for confusing the two sections====== Given: - A sticks to B - B doesn't stick to C My solution: As A sticks to B, one must be a magnet and the other iron. As B doesn't...

I solve problem where I use functions which are expanded upto some order. I multiply them, make square root and make derivatives or solve differential equations. What is the right way to deal with such problem? Shall I expand all functions after every step or work with unexpanded functions and...

How can space time emerge from nothing, I mean nothing in the absolute case is voide of any thing, I can imagine the BB where there is a primordial plasma the expands and creates the matter and space, but space time from nothing is beyond me, me being stupid and uneducated.

I am thinking no for the first question because the mother is not applying a horizontal force to cause the baby to move horizontally. Maybe yes for #2? Please help

Hello all. Right now I am taking physics 1 and were doing the Work-Kinetic Energy Chapter. I was just reading the derivation for the work done by a spring's force. I understand how to get the result but what i don't understand what to make of it. I understand that because a spring's force...

I don't know how to combine the x,y components with the equation of work.

In my State, the statute says 2 of 3 brake lights required. How is one brake light any brighter than 3 or 4? Is my perception of reality flawed? & though I say it is just as bright, when asked to give a reason why, I can not produce any answer. Is it because it is simply “there” or is it...

Question: I have tried this and got work function to e 5.1eV My concern is that for these type of questions, do I need to take into account the signs of some values; such as the negative sign for the charge of an electron? Or could I just take the magnitude for all the values Any help...

My take on it: I used ##W = Rt## where ##W## is work done, ##R## is rate and t is the time taken let ##W = 1## and ##t## be the time taken by lambert. for Lambert: ##1 = R(t)## ##R = \frac{1}{t}## ... (1) for Stassen: ##1 = \frac{r}{(3t/2)}## ##r = \frac{2}{(3t)}##...(2) from (1) and (2), ## R'...

What exactly is a measurement device and how does it carry out a measurement? For instance, in the double slit experiment, you always hear about particle/wave duality. When it's not being measured it behaves like a wave but when a measuring device is placed by the slits, it behaves like a...

I have been reading older posts containing "work done", but they don't seem to answer my doubts, or maybe I don't understand the answers because I need some visual pedagogical aids. I can sort of take the concept in, when we are dealing with a charge in an electric field, but when it comes to...

All of my working out is attached with the photos, I'm struggling to do anymore as the tutor hasn't explained anything like this yet. Any help would be much appreciated

If the first equation for force is not formatted please refer to the pic. I did not post my full attempt as the problematic equation leads to a complex integral. Should I be converting r vector into its univector. The two outlined equations refer to the force. I am making an error transforming...

As far as I know, a set of vectors forms a basis so long as a linear combination of them can span the entire space. In ##\mathbb{R}^{2}##, for instance, it's common to use an orthogonal basis of the ##\hat{x}## and ##\hat{y}## unit vectors. However, suppose I were to set up a basis (again in...

Hey, guys! I'm wondering, Iphone mute button, it's a slide switch and it's waterproof, can you explain me mechanism of it? Maybe with a drawing?

let ##f : R^3 → R## the function ##f(x,y,z)=(\frac {x^3} {3} +y^2 z)## let ##\gamma## :[0,## \pi ##] ##\rightarrow## ##R^3## the curve ##\gamma (t)##(cos t, t cos t, t + sin t) oriented in the direction of increasing t. The work along ##\gamma## of the vector field F=##\nabla f## is: what i...

Φ = hf = 6.626x10^-34x7.5x10^14 = 4.9695x10^-19 J

Why work done is area enclosed by graph of F v/s x on x Axis but not y axis. Suppose we apply a force on object which is proportional to displacement as ##\vec f##=## \vec x##²then area enclosed by Force and displacement on x Axis is integral of ##\vec x##²but on y-axis it should be integral of...

Just curious if anyone out there is using the old low pressure sodium vapor lamps for spectral calibration and diffraction work. I was surprised that I do not see any bench ready laboratory lamps from the usual vendors. I understand that the last manufacturer of the low pressure bulbs, Philips...

Here is the question: I have correctly calculated the power produced by the thrust force (P = Force x Velocity = 9.0 × 104W) , the work done by the thrust force over 3 minutes (W = Power x Time = 9.0 × 104 × 3.0 × 60 = 1.6 × 107 J) , and the gain in potential energy over this period (mgh =...

All I know is that when you press the button, the LCD icon displays an alarm icon which indicates the alarm has been programmed to sound at the exact time every 24 hours.

What do I see in my solution is : ΔW + ΔQ = W_pv + W' + ΔQ (A little difficult to perceive the useful work ) Work on the environment : -p0*(-ΔV) (WHY negative sign?, Is this the work ON the gas?) ΔV=nR (T0/p0 -T/p) By TdS = dQ ΔS + ΔS0 =0 Reversible case: ΔU= -T0ΔS - (-p0(-ΔV)) + W' (WHY...

Pardon if this is easy to find but I tried google with little success, so how can a fast reactor work without a moderator? Now I understand that a moderator is commonly used within thermal reactor which is why they are thermal in the first place as the neutrons get slowed down and their energy...

When we say that we apply force to a wall then we didn't transferred energy because of no displacement, but I think we somehow increase many types of energy of the wall. For e.g:- potential energy of particles in wall e.t.c. So according to me it means that we defined work only for mechanical...

Hi All, I am working on an engineering problem, where i have to calculate the total work needed to compress a volume of air (Locked in a cylindrical chamber similar to an IC chamber where the piston moves to compress the air mixture) I am defining the process with the below initial...

A year ago, we switched to Consumer Cellular. Since then, my wife and I have been getting Amber Alerts for the state of Colorado. We live in Florida, and Vermont. Our area codes are 518. We have no connection to Colorado. I just talked with Consumer Cellular customer service. They say...

A recent thread posed the question whether work is done by static friction in the case of an accelerating car. Before I had a chance to reply, the thread was closed on the grounds that the subject was "beaten to death". Undaunted, I am determined to deliver the coup de grâce here with a simple...

Hi there I have been attempting the parts to this question and I'm finding some trouble on how to answer the last part which is d)iii Here is what I have done for the rest of the parts and what I think I should start off with in part d)iii Thanks!

In textbooks or in lectures it is said that : Work can be either positive or negative: if the force has a component in the same direction as the displacement of the object, the force is doing positive work. If the force has a component in the direction opposite to the displacement, the force...

I was reading the chapter kinetic energy and work where I saw a derivation in which it was proved that work done=change in kinetic energy, so i understood from this derivation that work done is energy transfer by means of force but in this book kinetic energy is introduced earlier so as to find...

I'm asking for clarification, but it's my understanding, that of the thread below, and my college physics book Paul A tipler, that when walking or driving a car, the force of friction from the ground does no work. This makes sense in a car becuase the engine/fuel makes the power, driving the...

I found two formulas to calculate the work done. One is with this path integral: ## W_{AB}## = W(## r_A,r_B ##)=q* ## \int_{r_A}^{r_B} E*dr ## but here is the one I tried to use: ## W_{AB}## = q*Δ U = q*(## \frac {kQ} {r_A} ## - ## \frac {kQ} {r_B} ## ) Now here's my problem, what are...

I have a problem which consist in 1 bit RAM made of 3 MOSFETs. One of the questions is to calculate the maximum voltage that the memory element can receive. I have obtained the result by inspection (it is 4 Volts) but I'm unable to reach the same by applying the Thevenin Theorem. My...

Hello I am a beginner of Tex. The image made by LaTeXiT is cut off the upper part.(but Texshop goes well) If you can help me, please!

From what I understand, constraint forces do no work because they are perpendicular to the allowed virtual displacements of the system. However, if you consider an unbalanced Atwood machine, in which both masses are accelerating in opposite directions, you'll find that the tension force of the...

When calculating power, which is Work/time, do we consider NET work (work calculated based on net force) or just work done by the individual force that goes in the same direction as the displacement? If it's the first, then power is 3W. If it's the second, then power is 5W. Which one is correct?

Apologies for my fairly undescriptive title, I'm having trouble coming up with a better one. I'm simply trying to verify whether my understanding of this problem is correct. 1. Pushing the oven up a ramp 4m long would require more force (my reasoning here is based on the results of a lab which...

I am so confused.If F and d are both vector quantity.How come W is a scalar quantity?

I'm having a little trouble with part a) of this question: Since it is stated that the heating is slow, I thought it was reasonable to assume the process is reversible which means that the pressure in both sides should be equal. Consequently, $$W = - \int_{V_{0}}^{V_{1}} P dV = -...

According to the first principle of thermodynamics: ΔU = W + Q Also noting that: W = -P⋅ΔV (Question: This P is the initial pressure or the final?) To find V2: (P1⋅V1) / T1 = (P2⋅V2) / T2 → Therefore, (P⋅V1) / T1 = [(P/5)⋅V2] / T2 → (P⋅V1) / T1 = (P⋅V2) / (5⋅T2) → V2 = (5⋅T2⋅V1) / T1...

Have had a try at answering this question, and want to particularly know if I had done part e) correctly Here is my workings from the previous parts as I need to use some prior values that I have obtained before to do part e) For the last part, there were 2 ways that I went about it...

The proof of magnetic forces do no work is given in Introduction to Electrodynamics by David J. Griffiths like this My problem is why he has replaced d\mathbf{l} with \mathbf{v}dt? This substitution implies that the charged particle was moving with \mathbf{v} only and no force acted on it...

Here's my attempt for the first part: For the first body, the work obtained is ##W_1 = C_P (T_1 - T_f)## while for the second body, it is ##W_2 = C_P(T_2 - T_f).## So the net work obtained is the sum of these two: ##W = W_1 + W_2 = C_P (T_1 + T_2 - 2 T_f)## and that proves the first part...

What is the principle of operation of a quantum computer on a silicon chip? What are a qubits and how they connected and interacted between themselves? How does CMOS technology work in a quantum computer?

Since the assignment asks the work done by the gas, that should be equal to P1*(V2-V1) aka the area under the P1 line. Do I have to subtract the work done to the system or is this the solution already? If so, why do I need P2?

I know that you can get the answer through using Fs as 18 and solving for K, then subbing it into the equation for elastic energy. I was just wondering why another method wouldn't work. I tried doing it using the concept that Work is an equal to the Change in Elastic Energy, therefore Ee=xF...