Power Definition and 998 Threads

Hello there! So confused here, I tried to do some calculations with my power generation experimention. In terms of energy input, the energy output is lower. But in terms of power input, the power output is way larger. Thanks in advance! Cheers!

My question is: is the resolving power of an array of radio telescopes a quantum or a classical effect? The increase in resolving power of a single telescope, as aperture size increases, is easy to explain in terms of Heisenberg's uncertainty principle. But when we go an array of telescopes are...

(Just as clarification on what I am doing, I am attempting to use MATLAB to create PSD plots of time series from pressure and accelerometer sensors. Wave gauge sensors might still be helpful for me. I did not discuss accelerometer sensors in the post but maybe I could figure it out if I get the...

Hello all PF members! I was wondering about the power dissipated by resistor at high frequency which is: ##P=Re\left \{ U\cdot I^{*} \right \}=Re\left \{ \frac{\left |V^{+} \right |^{^{2}}}{2\left |Z_{c} \right |}\cdot (1-\left |\Gamma \right |^{2} )\right \}##, (1) where: ##Z_{c}## -...

This is a hypothetical question, but.. How much computing power would all the computers in the world combined have? Would you have a at least one YottaFLOP?

Hope you may help me to understand how detrimental to compressor motor would be if it operated at voltages exceeding the manufacturer's specified 400V by 12%? so 448V. I have vendor engineers saying since it exceeds 10% they cannot safely run the plant and of course the voltage monitoring relay...

In theory or at least in my head, it seems simple enough to me. A simple water pump, such as a pool pump pushes water through a pipe into a water turbine and recycles the water directly back to the pump. With some of the hydrogenerators I've seen out there, they produce far more power than the...

Surely the real efficiency of Fusion power is the percentage of neutrons that can be caught to extract kinetic energy from. I am assuming it is the neutron that is carrying the nuclear energy that can be recovered from the fusion reaction. Now I'm pretty sure neutrons cannot be focused, so the...

I was wondering, I have an engine that should keep a spring compressed. How can I calculate the power necessary for this? The work is Force x Distance, as there is no distance, there is no work, so no power... But obviously to keep the spring compressed the engine will have to produce a...

Hi. This is my first post. Thanks to all who give it a look. I am working on an application that has very stringent power output requirements. There is a rechargeable battery that I am trying to manage through a bi-directional boost/buck converter as is typical of many modern-day electric...

I am trying some projects that involve building some very simple electrostatic motors. I attached below figures of the kind of electrostatic motors I am trying to make. What I can't figure out is what kind of high-voltage power supply I should use, presumably 1000 to 10,000 volts is what these...

This is for safely powering up devices being tested/repaired. Supply is 240V rms single phase, protected by 32A MCB and 30 mA RCD/GFCI, then fused at 13A. There doesn’t seem to be a consensus online, and my EE and repair books just say I need both, without specifying order. I think the...

My work is attached below. I want to confirm my answer. Any help would be greatly appreciated !

To cover transformer loss at no load and maintain pf, we are needing 6kvar at day time and 9 kvar at evening. Is there any time based switch available, such that it can switch ON 3 kvar at evening, say 8:00pm and turn off automatically at 8:00AM morning

Hi, I was reading a newspaper article on the energy efficiency of commonly used air conditioners in homes. Then a doubt arose when the article informed me that there are air conditioners that have an energy efficiency of 10 BTU/watt. That means a classic 10,000 BTU/h air conditioning machine...

Good afternoon everyone, I need help with a certain calculation. How much power is needed to pull a 250lb load up a 45 degree incline at 5 mph. I am working on a project at school and would like to know what kind of motor we can use. Thank you very much!

Could electric cars be given longer range by radioisotope thermoelectric generators like they use to power spacecraft in deep space?

Hi there, I have a query about electric power in AC systems. I am Chilean, and over here the power supply is 220 V (rms) at 50 Hz. Some countries use voltages in the range 200-230, but others use 110 V or so, at frequencies of 60 Hz. There is no uniqueness, but all work. My question is...

Relevant equation: Since the potential difference V is independent of time and current I is steady, both the electric field and magnetic field are independent of time. Hence, the first term of R.H.S. of (8.9) is 0. If V >0, then ## V_{in} - V_{out} ## = V, ## \Rightarrow...

I is proportionate to E. r = 4.3xxm So I put 0.75I The answer is 49mW.. But I got 97.xxmW What is wrong?

How do I build diy laser power meter. I tried shining 5 milliwatt laser on photodiode. Photodiode is connected to led. Led never turned on.

https://pmt.physicsandmathstutor.com/download/Physics/A-level/Past-Papers/AQA-Old/Unit-5/June%202016%20MS%20-%20Unit%205-2A%20AQA%20Physics%20A-level.pdf One question on this the mark scheme seems to skip this step as the intensity is Power per unit area , when you make I sun = I quaser *...

I've replaced the charger for my DeWalt tools several times, and now I may have to go out and get a fourth one. One of them flashes a fault warning (steady slow flash), the other two do not light up at all. Now, I do not take care of my tools. All three of these chargers may have been exposed...

hi everyone. my uncle currently has a big "cylindrical rolling cooking pot" (imagine a cement mixer with burners at the bottom) that he uses to cook his stuff, ie sesame seeds. this cooking pot currently runs on gas. as he has been facing some issues with the gas supplier, he intends to...

I understand that when using the equation I^2 * R that current is meant to be constant in each component? I got the idea from this video So how can we use this equation to find the relationship between varying current against power? As the current is at a constant?...

I still did not understand this from my previous threads, what is the way to determine the instantaneous voltage across the cavity plates at any given moment, in a klystron I suppose the voltage would be proportional to the arriving electron bunch density which would determine the overall bunch...

Relative biological effectiveness is a factor that radiation dose is multiplied by to account for differences in biological damage by varying types of radiation. RBE is higher for alpha particles than any other, yet the relative penetrating power of alpha radiation is the smallest of the four...

I read the limits of typical ferrite cores and it seems that most sources claim that they tend to work somewhere up to 1 Mhz. Surely they work great under that frequency, but is there any material that could provide a core material for a wide frequency range starting from few tens of Khz up to...

Hi, I've attempted to solve the first part (see file Position 1) in mathcad, but have no idea if it's correct, at least for the first part, as I am assuming, that the steps will be the same for the rollers in the remaining positions. So if I can manage to calculate the first one correctly, I...

I know the answer, because they are not grounded and do not complete any circut, but I have a different analysis that I would like to explore. First, why do you need a closed circuit? Because if you have a battery pushing current along a wire that ends, electrons will accumulate at the end of...

My attempt: At node 1 > 4 = 6 + I1 Node 2 > I1 + I2 = I 2 Node 3 > 6 = I 3 + I 4 I1 = (V1 - 4)/21 In node 1, Using the equation for I1, V1 = -38V. I2 = (V1 - 4 - 1)/2 So, I2 = -21.5APower supplied by the 1V battery is P=VI P=-21.5 x 1 P=-21.5W I am not sure of my method, I just started...

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i am working on new project so i could use your help. Please and Thank you Tony

I see that DC power supply have voltage between it's + & - and its 24V. However, there is no voltage with ground. I don't understand - if device's "point" has some potential, why doesn't it give some voltage with ground (which has ~0 potential) I tried this with phoenix contact...

First, I calculated the power generated by the solar panel in one day. So since the intensity is 1.0e3 watts per 1 m2. 10% of this peak power is utilized so (1000)(0.10)=P-utilized=100W (per 1 m2) the solar panel has the efficiency of 13% so of this power only 13% is useful. P-useful=...

Is there any formula for calculating sound power? What does the A mean in I=P/A? Is the power of sound dependent on the area of its surrounding or something. I want to know if there's an equation for P like there's I=2π²a²f²ρv.

Hoow can one estimate the amount of steam required to generate certain amount of electical power mathematicaly?

This is going to be a very basic question, but something that has bothered me for a while. It was triggered again by this thread from @OmCheeto: https://www.physicsforums.com/threads/new-deccan-trap-turns-out-to-be-downed-power-line.970313/ Why is it that when a power line is downed, there is...

A link to this video popped up on my Twitter feed this morning: link The person who posted it asked for guesses as to what it was. I guessed; "Baby Deccan Traps?". She said "No." Then she posted the explanation: Maharashtra: Panic of volcanic lava trigerred after Beed locals witness rocks...

Hi. I'm having trouble with calculating (8.59) from (8.58) (## \vec H_{//} ## is simply ## \vec H ## in Jackson, but that shouldn't matter.) in Jackson. Specifically I think I'm not sure about parallel component of H field here. For example, shouldn't I have two terms for the...

Since solar and wind power are fluctuating energy sources not all of it goes into the grid when the consumer power demand is lower than that actually produced. This is a well-known drawback of solar and wind energy that everyone talks about. What I never found is an assessment of how much of the...

Hey all, I am doing some work to brush up my acoustics and one of the problems I came across this goes like this (translated, so sorry for potential grammar mistakes although I'll do my best to avoid them): A singer exhales 0.1 Litre Air per second. The 'overpressure' (pressure difference, so...

f(x) = 4x/(x-3)^2 Find the first five non-zero terms of power series representation centered at x = 0. Also find the radius of convergence.

What is AP layer in ansys redhawk ? I have list of layers I see in ansys redhawk tool, there are different metal and via layers , instances etc and there is a layer called AP in the end, What is this layer or where can I find more information bout it?

Again I am really confused, but I just put the traveling wave as: ##\psi(x,t) = Dcos(kx- \omega t)## for positive x ##\psi(x,t) = Dcos(kx+ \omega t)## for positive x Then I simply differentiated and plugged in ##x=0## ##F(t) = - T D k sin(\omega t)## and from this ## \langle P \rangle = T D^2 k...

My inital assumption was to just take T1 = 5600 and T2= 300K, find the maximum efficiency and then divide it by two and three but I don't believe this question to be that simple. I'm confused as to where the 750K fits in as I thought no matter what occurred in between the heat reservoir and heat...

So for part (a), I used the fact that 1/N = the period = T. I solved for the velocity, where i got v=2πRN. I plugged that v into F=(m v^2)/R, which is the centripetal force, but also the force of friction. My answer to part (a) is 4(π^2)mR(N^2). I'm a bit confused on part (b). I know that...

Hello Friends, I have been wondering, is it possible to construct a motor, and attach a coil to it, such that with the motion due to the rotation of the motor, it generates a excess of energy that can be used to power the motor in turn, basically, could i use the excess to charge a battery that...

Had not seen much discussion of this, but of course PV cells are semiconductors with a finite life and will have to be disposed of within a decade or two https://www.scmp.com/news/china/society/article/2104162/chinas-ageing-solar-panels-are-going-be-big-environmental-problem

Homework Statement Once under way at a steady speed, the 1100-kg elevator A rises at the rate of 1 story (2.74 m) per second. Determine the power input Pin into the motor unit M if the combined mechanical and electrical efficiency of the system is e = 0.76. Here is a link to the diagram for...