Calculations Definition and 982 Threads

Given the AC Induction (asynchronous motor) in 3 phases: Parameter Value Pn (Nominal Power) = Pmechanical (output power at the shaft) 5 kW = 5000W uls (Voltage through the stator line) 220 V fstator (stator frequency) 50 Hz p (Number of pole pairs) 2 LFe (Iron loss) = Lmechanical...

Hi If x(t) is considered to be small so that higher powers ( greater than 2 ) can be neglected in a calculation does that also imply that the time derivative of x(t) can be considered small and powers greater than 2 be neglected ? Thanks

So i need a little bit of help with a problem. I have a tapered shaft connected to a gearbox and i need to caluclate the deflection of the shaft and the max shear stress of the shaft. the total length of the shaft is 500mm the diameter is 35mm and tapers to 28mm with the taper length of 90mm...

Hi, I have a 1 HP motor spinning a turntable (just a wheel) weighing 1kg, diameter 25cm speed 2000rpm. (Arbitrary specs). If I have to spin a turntable with the same weight (1kg) but double the diameter (50cm) at the same speed, would I necessarily need a motor with double the power (2 HP)...

Guys I have Problems with this task The arrangement consists of a point charge Q at a distance (x0, y0,0) from the origin and two perfectly conductive surfaces in the (x, z) and (y, z) plane a) Mathematical description of the space charge density p of the original and mirror charge using the...

I apologize in advance for any errors in my concepts or assumptions. Feel free to correct me wherever I am wrong. Thanks in advance for the help. There is a vertical shaft which will be operated at around 600 rpm (N) which can be achieved in 2 seconds (or even 4 just an assumption). The shaft...

Let me start off by saying I decided to post this in the aerospace engineering thread because it directly deals with thrust, even though it is not for a plane or similar. I have two equations that I can use to calculate the force on a baffle of a muzzle brake, Equation 1, from The Engineering...

I would like to be able to determine the current through a device for a given junction temperature. I am looking at a datasheet and notice that it gives the device power dissipation with different case temperatures. Since the maximum junction temperature is 175 C, I believe that means that lower...

Ok, so basically my task is to calculate the apparent diffusion D based on experimental data, which is kind of easy, BUT the problem is with unit of b... Gamma is gyromagnetic ratio and can be expressed as: (s*T)-1 or MHz/T --> but I am not so sure, teacher did not specify Delta is the pulse...

Hi all I am trying to calculate Source Level 'SL' of a underwater acoustic Cylindrical Array with multiple Transducers. The array has 03 Rings with 32 transducers in each Ring. The spacing between each ring is around 0.18m whereas Dia of each Ring is about 1m. Each transducer is being driven...

I've created a concept design of a subsea pumped hydro storage system, and need to use the flow rate in order to calculate power output. I can calculate the energy storage capacity using ##E = mgh##: $$E = mgh = 25675000×9.81×200 = 50374 MJ = \frac {50374MJ}{3600} = 13992 kWh$$ I've attempted...

Inflatable SUP boards, LEI kites, Inflatable kayaks, and so on get their stiffness by having two layers of airtight materials separated by pressurized air. And it gets stiffer the higher pressure you can contain, or by increasing the separation between the materials. The simplest way to look at...

In Anthony French's book, Newtonian Mechanics, while explaining the non-Euclidean nature of the 3-d space, he poses a problem (I have rephrased it slightly): Suppose you are on Earth's equator (r = 6,400 km) at the prime meridian (point I). You first walk along the equator 1000 miles east and...

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...

I have given a metric in terms of the spherical coordinates ##(r, \theta, \phi)##. The problem is that I need to find the Riemann/Ricci Tensor and Riccl Scalar from the given metric by using code. I wonder what type of language (such as Python, Mathematica, Matlab, etc.) I should use it to make...

Let us suppose we are given two vectors ##A## and ##B##, their components ##A^{\nu}## and ##B^{\mu}##. We are also given a minkowski metric ##\eta_{\alpha \beta} = \text{diag}(-1,1,1,1)## In this case what are the a) ##A^{\nu}B^{\mu}## b) ##A^{\nu}B_{\mu}## c) ##A^{\nu}B_{\nu}## For part (a)...

So basically, I got close to a zero for my solution to this problem. I'm guessing based on the posted solutions that I wasn't able to get partial credit due to the fact that my coordinate axis was aligned with the slender bar and not in its usual perpendicular position. This resulted in...

Consider the attached screenshot. The work function of graphene is assumed to be 4.5 eV. 1. Does the work function correspond to the binding energy ##E_B## as given on Wikipedia? What is ##E## in ##E−E_F## in the graph on the right? 2. "...the Fermi level at the K-point..."; is this the point...

A water cooled plate condenser, condensing refrigerant. Heat exchanger (condenser with plates) characteristics: Description symbol value value (converted) number of plates np 28 number of channels nc 27 number of water channels nwc 14 number of flowing channels for refrigerant...

I know at balanced condition, the current flowing through galvanometer = 0 and R1 . Rx = R2 . R3 What I want to ask is how to analyze the circuit until we can conclude the current will be zero. I have learned about Kirchhoff's 1st and 2nd law and also about potential divider. I am guessing...

I read in 2 books that 4 atoms of Hydrogen fuse and give 1 atom of Helium and 2 electrons, and these 2 electrons convert to light. And that the mass of the Helium is less than the mass of the 4 atoms of Hydrogen, thus that the mass lost converted to light too. But I sum up the masses of...

Hey! I am trying to determine the bond length of acetylene by analysing the vibrational spectrum of both H-Acetylene and D-Acetylene. I was able to calculate both the rotational constant and the moment of inertia but am stuck now as to how I get to the correct solution. On the left is the...

Hello, Im trying to calculate the torque needed for a system that i want to design. i want to raise and drop a weight of 800 kg. Ive made some calculation but I am not certain i did it right. I think I am on the right track but i feel like the numbers are a bit high. I have a hard time finding...

The only knowledge I have about such reflection questions is theta=2theta. But I missed class when this was thought. Please I need help and guide

Hello, thanks in advance, I do many many things, jack of all trades but master of none. Would some one be willing to help me with some formulas and calcs for making my own linear solenoid? I can give the final specs I'm after then I could use advice on materials and other variables. I'd like...

Like I said, I was taught during the TCP congestion control lecture what is the slow-start strategy, how it works & looks in a very high level, we never saw anything related to parameters and calculations, and after the test she gave the entire class a bonus of 35 points because she knew it...

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) =...

Hi Physics! And again, thanks for the membership! I’m about to build a robot just with some old parts I have. The main thing is the motors. I have 2 DC Motors Specs below. (It’s a MFA975D Series with gear ratio 49:1) Operation range(Voltage): 12V No load = 147RPM Nm = 1,8 Stall Torque =...

Hello, https://www.researchgate.net/figure/Top-Graphene-nanoribbons-with-zigzag-left-and-armchair-right-edges-with-disordered_fig1_258105786 With what kx/ky values are these band structures plotted? The energy dispersion of graphene is given by this , yet I am confused to what kx/ky value...

Are there any websites that might have load bearing calculations for metal square tube columns. Thanks in advance...

Hi. I want to design a custom Geroler motor for a hobby project of mine, but I want to calculate the torque it can produce at a given pressure and for that i need to calculate the motors displacement, but how do i do that?

I have a platform which can lift 600 kg (the platform itself weighs 95 kg so their combined mass is actually 695 kg) at 0.75 m/s up to around 37 m in height at a maximum angle of inclination of 87 degrees. The issue I'm coming across is determining the power required to lift said mass as the...

Hello all, I've been on the hunt throughout the scientific literature for a little while now for some information, but I'm coming up empty. I'm hoping there's some expertise here in the area of altimetry as it relates to sea level calculations. More specifically, I'm trying to find the actual...

I am using square roots, however, I am confused over how many significant figures (s.f.) to keep. Suppose I have ##\sqrt{3.0}##, which has 2 s.f. From three different sources, I'll put a summary in brackets: https://www.kpu.ca/sites/default/files/downloads/signfig.pdf (if 2 s.f. in the data...

Hi all :) Can't find an online calculator to properly do this. I know basic sqft - if I have a room that is 12x12, the sqftg is 144. Easy. But... I am retiling the shower in my bathroom. Three walls, and not the ceiling nor the floor. I need to speak sqft to the tile store. Two of the walls...

Is there a book that emphasizes performing calculations with tensors in modern notation?

Hi, I came across some interesting frames recently. Here they are: I wonder if all these frames can be solved analytically. If yes then how to do it ? Examples a) and d) are planar frames with diagonal members while b) and c) are spatial frames: b is subjected to uniformly distributed load...

Hey everyone, I have a problem with sizing a clutch for my machine. My problem is, I don't know how to calculate the needed value (Nm) for the clutch to withstand the torque affected by the flywheel. I have a flywheel that weighs 90kg and is 600mm in diameter. It is rotating at 500rpm...

I think i(t)= i1f + i2f -ig. I want to be sure of it and I also need to compute v(t), but I don't know how to.

Summary:: I'm going through my homework. I am confident I have everything correct except for my boiler efficiency. It seems too high at 99%. I would like to think my logic is sound but it can't be right. A boiler is designed to generate steam at 5 MPa and 400oC. A fuel is selected with a...

Hi I have answered the question and have attached my working . I'm not very sure about part b. I generally need someone to check my working and let me know if I've made a mistake. Thanks

Hi, I have a question regarding plastic bending of beams (assuming bilinear elastoplastic material - with or without hardening) . In literature one can find calculations of load capacity for those beams. But what else can be calculated in such case ? Stresses ? Deflection ? Where can I find...

Am I right to assume that the equivalents for phenyl magnesium bromide would be 3 (magnesium, bromobenzene and ether (?)) And the number for 2-phenyl-propanal 1 as it says "...was added to 2-phenylpropionaldehyde" which is the same thing as 2-phenylpropanal? I don't know if I understood this...

Hi, advanced FEA programs allow their users to perform fatigue analyses. However, there are still many programs where such simulations can't be performed. I've heard that in such case one can use results obtained from regular linear static FEA to calculate fatigue life manually. Theoretically...

Apologies for the noob question. The frequency of the human body can be calculated based on weins law as follows: Wavelength = 0.002898/310 = 0.00000934838 m Plugging this into the equation λν = c we get frequency = 299792458 / 0.00000934838 = 32069 Ghz Elsewhere, I see that the resonant...

I cannot understand the solution at https://www.aapt.org/physicsteam/2015/upload/E3-2-5-solutions.pdf, because the solution is terse and skip steps (at least i think so). I figured out that the name of this transfer is "Hohmann-Transfer Orbit". A detailed walkthrough would be appreciated. If I...

I have a question related to linearity of power spectral density calculation. Suppose I have a time series, divided into some epochs. If I compute PSD by Welch's method with a time window equal to the length of an epoch and without any overlap, I obtain this result: If I calculate the...