Power Definition and 998 Threads

Basically this would be a closed loop geothermal system for electrical power generation. The system would consist of 2 Horizontal Wells connected creating a U-shaped closed loop cycle using thermosiphon effect, with constant recirculation. It's not really a conventional geothermal power...

Hello everyone. I have to determine the tank volume and power requirement of a tank. The teacher has done it the following way, however, I don't understand the process.

Work is the dot product of force and displacement (let me set aside the path integral). If a rock of 2 Newton is lifted up 3 meters, the work is NEGATIVE 6 Gravity force is down, displacement is up, the dot product is negative and we can say: "The force of gravity does work = -6" If a rock of...

I have just completed a paper in my English class about nuclear energy and I would like to hear about other peoples interest of the topic of using nuclear energy. I would like to come out and say I have found a lot of information regarding how safe they really are and how efficient the plants...

I am reading Planck 2015 results. In particular, I focused on "Power law potentials" subsection. The issues I have are 1. I do not understand why the validity of the model can be determined by the value of the ##B## mode. 2. Why the ##B## mode values ##\ln B = −11.6## and ##\ln B = −23.3## for...

I am practice stick fighting for self defense. I have a question I don't know how to judge. Say if I have a 6oz and a 12oz stick both 28" long. I swing them to hit an object, assuming I have the same strength, obviously the velocity is faster with the lighter stick and slower with the heavy...

Each operator has a domain, so for a power of an operator to exist, the domain of the operator must remain invariant under the operation. Is that correct? mentor note: edited for future clarity

VR = IR = 400 [ 29*10^-6 * 800 * 10^3 ] = 9280 P = IV = 400*9280 = 3.7 MW I was able to calculate the correct answer from the above, but why can't I use the equation P= V^2 / R?

Assuming the position x = 0 if no air gap, max stroke of plunger is L. Bordery conditions: x(t=0) = L, x(t=T)= 0. Given magnetic force F(x) = kx(t)^-2, here k is constant. If uncontrolled, there is big crash noise afer solenoid actuated, so I wish it pull plunger at constant power. Help me find...

Hi, When I look at some circuits, I often get overwhelmed when there are transistors and diodes and I have no idea how to make much sense of it at a detailed level. For example, in this power stage B amplifier, what is the point of the resistors ## R_1 ## and ## R_2 ## in the circuit...

r = 2.5 l=10 cm angle = 0 (maximum connecting rode elongation) w = 0.5 (30 rpm) n=10/2.5 = 4 so the acceleration is 1.5×0.5×0.5(1 + 1/4 ) = 0.4 m/s friction force = 10*9.81*0.3 = 29.4 Newton. Crank force is the mass of the object into acceleration. So crank force = 10 × 0.4 = 4 Newton...

Dear PF Forum, I watched this video 10 ^ 10 ^ 10 ^ 5600 The narative says, It is 1 followed by 5600 zeros But that's not what I think, I think it is 1 followed by I don't know. What does this number means? Is it A: 10 ^ (10 ^ (10 ^ 56))) or B: ((10 ^ 10) ^ 10) ^ 56? It says that "As...

There is an excellent math teacher out here in Aus (he won young Australian of the year) who makes good videos. Here is one about the old conundrum 0^0: As you can see in my comment, I'm afraid I have to disagree with Eddie here. 0^0 is undefined because you get different answers depending...

Hi, I wanted to have a precision about a question that has been post on this relation between P(k) and C_l The author writes the ##C_\ell## like this : $$C_\ell(z,z') = \int_0^\infty dkk^2 j_\ell(kz)j_\ell(kz')P(k)$$ I don't undertstand the meaning of ##z## and ##z'## : these are not...

In the context of Survey of Dark energy stage IV, I need to evaluate the error on a new observable called "O" which is equal to : \begin{equation} O=\left(\frac{C_{\ell, \mathrm{gal}, \mathrm{sp}}^{\prime}}{C_{\ell, \mathrm{gal}, \mathrm{ph}}^{\prime}}\right)=\left(\frac{b_{s p}}{b_{p...

That is how much more power would it consume if one was to try and produce the same amount of heating power with just the waveguide holes and no walls, so no reflections?

I have a "high votage" converter with components at different voltages distributed throughout. I have some sensors that need to be powered in one location that's some distance from its power supply. I want to minimize (or eliminate) the high voltage wires routed throughout the converter. My...

My dad has been asking about some speakers for his boat, something that will move a bit of air, not too big though. I'm thinking 1x12. He also wants it bluetooth and powered externally, so it doesn't drain the boat battery. So I'm thinking 1x12 speaker in a small box that can fit inside the...

We know linear spring force F = kx(t), k = spring constant, during any moment t of energy release. displacement x(t) = ʃv(t)dt the power p = F*V = kx(t)v(t)= kv(t)* ʃv(t)dt My question: Is there a mathematical function of special v(t) to make power p constant?

The heat pump comprises of the 4 components: evaporator, compressor, condenser and expansion valve. Thermal power required to heat the building: 12.1 kW at condensing temperature tc = 44.3 deg C For the evaporator: vaporizing temperature tv = -7 deg C Subcooling temperature for the heat pump Δ...

Should i use P = V.I or P = Vrms.Irms.cosφ ?

This is one of those 'oh, I am not sure I know the answer' kind of thoughts. The strength of magnetic flux in a transformer core is a function of volts per turn, Faraday figured that one out. So, if I have a light load on a secondary (let's say it is pure ohmic for now, let's not confuse it)...

My thinking was that the power produced by a falling object is P=Fv=(-mg)(-gt)=mg^2t. So it depends on t, ie the "counter power" must also depend on t if it is to balance it, right? But author's solution is a constant. I know I am making a mistake somewhere. Note: Apologies for the lack of...

Mentor note: Since the technique used here involves differentiation, I moved this to the Calculus section. Hi, I was trying to do the problem below. I was following the approach presented in this answer. I assume the approach is correct. The answer I ended up with is clearly wrong. Where am I...

We usually talk about ##F[[x]]##, the set of formal power series with coefficients in ##F##, as a topological ring. But we can also view it as a topological vector space over ##F## where ##F## is endowed with the discrete topology. And viewed in this way, ##\{x^n:n\in\mathbb{N}\}## is a...

I have been studying the representation of generators in power flow studies and I would appreciate your comments in this thread. From the book Fitzgerald & Kingsley's Electric Machinery, I understand that there are unsaturated and saturated reactances. In section 5.3.2 of the book it is said...

Author solution:

How did you find PF?: Online [Thread moved from the New Member Intro forum, so no Schoolwork Template is shown] Hi. I'm new and am trying to solve a simple question 'Find the max power of a train engine traveling level at 50 metres per second if total resistance to motion is 30 KiloNewtons...

In school I learned about impedance: where.. $$Z^2 = R^2 + X_{net}^2$$ but this was the only triangle I recall learning about. The picture below I definitely do not recall. from this Link The only quantity I am familiar with is the x-axis (Power). If someone could explain...

I started of by trying to find the work for I got stuck because I did not know how to solve for the Force. I solved for the distance by doing 3=d/5s which gave me 15m. but then I couldn't figure out where to go next in the problem because I don't know how to solve for (f) so an explanation would...

Why can't we calculate use I*ε to obtain the power?

Summary:: How does the air-gap affect the efficiency ? For a wireless power transmission system, to what extend does the efficiency and coupling parameters get affected by the distance between the coils? What can be done to increase the power transmission or efficiency regardless of the value...

Since the power generated by both primary coil and secondary coil would be the same in a transformer, so I used the relationships stated above to deduce the resistance R in secondary coil. P1 = N2^2 *100 = 100^2 * 100 P2 = N1^2 *100 = 500^2 * R R = 4 Let me know if my thoughts here are...

I calculated in the following and got the correct answer. However, I wonder whether this way is correct or not. Thanks! PR / Pavg = Irms^2 * R / Irms^2*Z = 15 /33.36 = 0.45

I have calculated the force equation on the x-plane which is f - mgsin(30) - friction force = ma and from the equation vf = vi + at resulting a = v/10

Has anyone reviewed the Lectro Saver -Electricity Saving Box. Its a $30 plug in gadget that claims to smooth out incoming power and use it more efficiently so that your energy bills are drastically reduced, They claim it is inspired by Nikola Tesla.!

We need all the project including all details with schema, If you are talented for drawing the project, please contact me. 50/62,5 MVA, 154/33 kVA

https://www.nbcnews.com/science/environment/one-texas-storm-exposed-energy-grid-unprepared-climate-change-rcna289 The link above is an opinion piece that discusses the possible lessons from the experience in Texas. FYI: This was a textbook system wide grid failure, caused by off the charts...

I have to use a BLDC motor combined with a BLDC motor driver (X-NUCLEO-IHM08M1) The motor has a rated current of 7.3A. So i am planning to use a 36VDC 13.9A power supply (SMPS). The problem is that the PS that i want to use has a "HICCUP mode" for overload protection and not a "constant current...

My plan is to power the secondary with my 120VAC generator and use the 240VAC primary connection configuration and use the H3 and H8 taps as the neutral.

This is an enormous failure, comparable to the "Great Northeast Blackout of 1965". Rolling blackouts are being imposed at a time when millions of residential customers need home heating. The oil refineries shut down. Expect gasoline/diesel shortages and price spikes nation wide in a few days...

I thought about this for some time but I can't seem to really understand the cause. Now I remember some time ago using a transformer for my self made soldering iron, I wound it to have the right temperature at about 45 VAC input but I guess I missed a bit , so that when I connected it to the 45...

The v(t) = 120##\sqrt(2)\sin(2\pi 60t)##. Let the resistance of the heater be "R", then the rated power = 1500W. The rated power is the average power 1500 = ##\frac{120^2 *5 * 60} {12*60 * R} ## ->eq1 R = 4 Ohm. a. Instantaneous power is ##P = \frac{v^2} R ## -> eq2 ##P =...

Heat cannot be removed by liquid-to-gas heat exchangers since there is no substantial atmospheres on the Moon or on Mars. It cannot be dissipated by venting steam since there is a critical water shortage. It cannot be dissipated by rocks or soil since both are essentially thermal insulators. It...

For a current i(t)=I_0\sin(\omega t+\varphi_0) period is ##T=\frac{2\pi}{\omega}##, Power is defined as p(t)=Ri^2(t). So period of power is not any more ##T=\frac{2\pi}{\omega}##. Why then average power is P=\frac{1}{T}\int^T_0p(t)d t. Why are we using the period of current and not of the...

Hello! So what I've tried to tackle this problem is derive the equation,set it equal to zero,find a value for v and than put it in the second derivation.So when I derive this I get $$ \frac{v^2+9-v *(2v)}{v^4+8v^2+16)} $$ Now if i set that equal 0 and try to find a value for v I get this. ##...

The below are the formulas i have seen from the book, but no particular formula for the peak power Instantaneous power ##p(t) = v(t) i(t) W## ->eq1 Average power ##p(t)_{avg} = \frac{\int_{t_0}^{t_0+T} p(t)dt} T W## ->eq2 a. Instantaneous power ##v(t) =A\sin(\omega t)## ->eq3 ##i(t) =...

My attempt at solving this question: I realized my attempt is wrong however I just don't know how to proceed in the first step. How can I calculate the phase shift? and find Voltage and Current in phasor form??If I know that, then I can use power factor formula: pf=Pav/V*I