Power Definition and 998 Threads

In my approach, i have ##F_{Resolved} = 300 \cos 60^{\circ} = 150## Newtons. I also have, ... from ##v=u +at## ##2=0 +6a## ##a= \dfrac{1}{3}##. ##F=ma## ##F=30 ×\dfrac{1}{3} = 10## Newtons Therefore, ##P= \dfrac{(150+10) ×6}{6} = 160 ## W Insight is welcome...

Hello, if I have an available amount of Joules say 10 I believe I can produce 10 watts for 1 second. Is it possible to use some kind of step up system using my available 10 Joules to step up to 20 watts but for only 0.5 seconds ? And so on like a kind of electrical ratio system.

The definitions of power and work in continuum mechanics are: $$ W = \int T \cdot u dA + \int b \cdot u dV (1) $$ $$ P = \int T \cdot v dA + \int b \cdot v dV (2) $$ ##u## is the displacement vector, ##v## is the velocity, ##T## is the cauchy stress tensor, ##b## is the body force ##A## is...

I'm confused about the wording "runs one-fourth of the time". My professor said we multiply the Q_L by four, but I don't get it conceptually.

This could be a typical setup: We're transmitting a signal of 100W measured directly out of our Pa / Matching network into coaxial feed line. The feed line has a 52.2 -J0.31 Ohm impedance. The length of this coaxial feed line is 100'. The matched line loss of this feed line is .709dB/100' at...

Hello everyone, I’ve been working on modifying the RF Power Amplifier circuit, and I’ve made good progress (schematic is attached below). However, I’m now facing a small issue – I’m currently getting an output voltage of around 9Vpp, but I need it to be in the range of 15–18Vpp. I’ve tried...

By applying some simplifications, the power ##P## of a body moving at a speed of ##v## at an incline of ##\alpha > 0^\circ## can be expressed as: ##P = P_{acceleration} + P_{friction} + P_{gravity} + P_{air} = (ma + mgsin(\alpha) + C_{rr}mgcos(\alpha) + 0.5C_dA\rho v^2)\cdot v## If we would...

So , max power is dissipated when the load resistance and thevenin resistance becomes equal such that $$P\leq \frac{V_{\text{th}}^2}{4R_{\text{th}}}$$ Then i applied the 'star delta' transformation by converting the 'delta' ABC to 'star' ABC . From there , by loop current method , i got...

How do we calculate power dissipation for AC termination on a clock signal? The resistor is dissipating only at the edges(assuming a square wave).

$$P=IV \left [ \frac {cos\phi} {\sqrt{1+THD^2}} \right ]$$ The reason for asking is, I can’t find the equation written out in full like this. A friend wants to know why his generator is rated in kVA. Having done basic school physics, he’s familiar with P=IV in the DC steady state, so is...

There are reports of a series of problems at the Rostov Nuclear Power Plant. Shutdowns, regional power outages, radiation releases, and runs on iodine. Is 1.5 million curies a lot to release?

Joining this forum to learn and talk about next generation nuclear. I'm a chemical engineer currently in pharma (process R&D for small molecule drugs, a rather different field, at a Japanese company) interested in contributing to next generation nuclear. Especially interested in chemistry...

Hi! As written in the summary, I would like to get feedback about my approach to an issue I wanted to explore. In the example I am using cycling, but principally the same theory would apply to similar sports as well. So, the problem was that I wanted to investigate whether the athletes' W/kg...

How do you get these scalings for the matter power spectrum?$$P_{\Delta}(k) \sim \begin{cases} k & \quad k < k_{\mathrm{eq}} \\ k^{-3} & \quad k >k_{\mathrm{eq}} \end{cases}$$(N.B. ##k_{\mathrm{eq}}## is the scale of modes that enter the horizon ##k \sim \mathcal{H}## at matter-radiation...

Good morning, I followed this thread https://www.physicsforums.com/threads/halbach-array-arrangement-for-a-transformer.979745/, about wireless power transmission using a Halbach array and @Baluncore answers are were very satisfying. Here are two configurations, the first is a resonant dipole...

I have a nozzle through which a water vapour passes at 503 metres per second with a density of 0.051 kg per cubic metre giving a mass flow rate of 0.00129 kg per second. Using half mass times velocity squared I have an answer of 163. Is that answer 163 newtons and if it is how do I convert to...

Is this wrong?

I am trying to simulate an OLED via Atlas SilvacoI want to know how to convert light power (watt/um) into luminance (cd/m2) or the syntax to do that in Atlas silvaco.THANKS

Consider this proof: Is it a valid proof? When we divide by ##z##, we assume that ##z \neq 0##. So, we cannot put ##z=0## on the next step. IOW, after dividing by ##z## we only know that $$c_1+c_2z+c_3z^2+...=d_1+d_2z+d_3z^2+...$$ in a neighborhood of ##0## excluding ##0##.

Hi, How to convert 51065 foot pound per second to Newtons, not Newtons meter per second?

In principle, the ring is, at any instant, a beam being loaded in the centre, and in a failing state. Thus, to drive the material continuously through the rollers, Force x Velocity = Work done/time = power. 60.P/2.pi.N = T The units pan out, but is the concept correct? The faster the work is...

All else, equal, does an airborne technique transfer more power? I don't think it does but an instructional tape from the 80s claim so

I read an interesting article on progress in making transmission lines more efficient: https://reneweconomy.com.au/super-cheap-transmission-upgrades-could-double-capacity-and-open-floodgates-for-renewables/ While, of course, we do not discuss politics here, this new technology has many...

Hello everyone, I would like to ask some questions regarding my thesis. I have a problem identifying which load I should use to calculate the power output of the small generator. I use an Archimedes screw turbine as the prime mover of my generator, and the water flow is low in my locality...

This question has multiple parts and according to all the work done up to this point... How much work W does the motor do on the platform during this process? 1885 J What is the rotational kinetic energy of the platform Krot,f at the end of the process described above? 1885 J What is the...

many pulleys at various angles multiply the initial power of the winch

Hello, It has been difficult to find a clear answer to this question. I've found some sources stating that the power of a sound wave depends upon both amplitude and frequency. I've found other sources stating that the power of a sound only depends on amplitude. I've found sources stating...

Basically, I tried to find the solution by calculating P=Fs/t, where F= 2250 and s is the distance traveled in the 12th second and that result differs from the result I get when I calculate the power using P=Fv. ##F=ma=1500*1.5=2250N## ##s_{12}-s_{11}=...

So for Q1, I answered down (towards Earth) but the solution says there is no acceleration there. For Q2, I answered mgh, but the solution says it's mgh/t, which is power, right? I just want to make sure I'm not super confused. Thank you.

The definition of work and power done over a continuous body is: $$ W = \int Tn \cdot u dA + \int b \cdot u dV $$ $$ P = \int Tn \cdot v dA + \int b \cdot v dV $$ ##T## is the stress tensor, ##b## is the body force, ##u## is the displacement vector, ##v## is the velocity, ##n## is the normal...

For part (a) the answer key is saying it's 40 hp. I'm having trouble understanding this. So the car accelerates to 15 m/s, then it stays at that velocity of 15 m/s, needing only 20 hp power to overcome the work done by air resistance. Supposing the car then accelerates to 30 m/s and stays at...

I've been trying for 45 minutes and doing research but I can't even find a start to how to approach this. :( [Mentor Note: New user reminded to always show their work on schoolwork problems. That work is shown in a subsequent post below]

How much power (Megawatts) would it require if we were to create a magnetic field as large and strong as the Earth's magnetic field?. I haven't learned how to calculate this, but just curious.

For those that have to vacuum large spaces often have to use many different outlets and worry about running over their own cord. Is there a battery pack one can strap to their back to power a vacuum cleaner? Or would that amount of power tide to a person be dangerous?

From the previous question I got the star is giving off around 4.01*10^27 W. I am unsure how to find the answer it asks for. Please help.

I used the formula P = 1/2 mv^2/t. Then multiplied by s on both sides to get P.s = 1/2 x mv^2/t x s ==> P.s = 1/2mv^3 and then expressed v = root(2gh) and equated. BUT I Got h = (1/2g) x (2sP/m)^2/3 but the answer is h = (1/2g) x (4sP/m)^2/3 Any idea where I am going wrong?

I've tried to solve this exercise but I haven't used one of the properties of the system (the displacement of the masses) so I don't know if I'm wrong about my procedure. First of all, we (obviously) know that $$ P=P $$ And since we can express the power of a force in two different ways, we...

Hi, I was having a discussion with a colleague today now I'm second guessing myself. My understanding of nameplate kVA is that it is based on 'ambient temperature, temperature rise, heat transfer, thermal mass, thermal time constant, materials used, and expected transformer life'. However...

I'm curious as to why the average power is not negative in this scenario, since I thought the friction force is in the opposite direction of velocity. As far as I see friction force is the only acting force in the problem, but I may be wrong. I solved this by simply doing (Friction Force *...

Hello, I have a problem wrapping my head around the relationship between frequency, power/pressure, and displacement. Let's say I have two sine waves that I generated in my computer: A 50 Hz tone and a 100 Hz tone. Let's say they both have an amplitude of 1. Therefore, they will both have...

In a simple circuit consisting of a battery and a resistor, current will flow if the circuit is closed. Resistor uses the energy provided by the battery, creating heat with a power ##P = UI##, where ##U## is a voltage across the resistor and ##I## is a current through the resistor. In my...

In the picture below

I equated dP/dR to 0 and find the solution for R. Is the solution correct?

The answer in the book is 400w. It said that ##P_{av}=Fv_{av}cos(F,v)=mgv_{av}cos(F,v)=400##w and F is upward force that is applied by elevator. Should velocity of the elevator be constant? Because it said that we have F=mg.

For instance this Power Cube device. Is it capable of reporting EXACTLY how hard Francis Ngannou punched, or will it be biased towards mass or speed and overestimate one of the components? How "off" from the actual physics of reality do you expect such a tool to be? 5%? 10%? 20%?

Hi, So, PC powered of all the sudden, wont power on. Battery had not been charging when PC was plugged in. So, can I conclude neither battery nor power cord are working well? I guess my options for doing something to have battery recharge are limited, given PC won't power on. Do I have any...

Are my equations correct? And my process of how I should solved this problem?

I just don't understand should I take u relative to the plane or relative to the ground. I tried to solve it like this: $$p_{final}=m_{0}v-m(u-v)-M(u-v)$$ $$p_{initial}=m_{0}v$$ $$\Delta p=-m(u-v)-M(u-v)$$ ##m_0## is mass of the plane. $$F=\Delta p$$ $$F=-m(u-v)-M(u-v)=(m+M)(v-u)$$...

hi all how do I prove that $$ <A^{n}>=<A>^{n} $$ It seems intuitive but how do I rigorously prove it, My attempt was like , the LHS can be written as: $$ \bra{\Psi}\hat{A}.\hat{A}.\hat{A}...\ket{\Psi}=\lambda^{n} \bra{\Psi}\ket{\Psi}=\lambda^{n}\delta_{ii}=\lambda^{n} $$ and the RHS equal: $$...