Calculations Definition and 983 Threads

Here is how I tried to solve it but I don't know how I got formula for disc. Before this I tried to solve for half disc using a vertical element and it worked but not for this. Why?

I have a question about one of the steps in the calculations. For context about where in the calculations I am, we assume that a particle is subjected to a potential energy function that is infinite everywhere along the ##x##-axis except for a line segment of length ##l## where the potential...

I'm not sure what forum to put this in. Sorry if I have placed this in the wrong forum. This topic seems to require understanding of both electrical and mechanical, so I'm placing this in the physics forum. Knowledge of this subject doesn't appear to be too common, so I'm not posting it in the...

[Mentor Note: Thread moved from the schoolwork forums to the technical forums, since it appears to be a real-world problem] If I have a water well 55m deep I want to suck water by gravity without any pump. I put a barrel of 85 liters and connect it firmly to a pipe of 55m length going into...

Hello, due to my age it's been at least 40 years since I needed to carry out in-depth calculations where I could use some support. Hopefully some of you out there can point me in the right direction when the going gets tough. The forum attracted me due to the wide variety of discussion topics...

Hello, I am quite interested in Raman spectroscopy. For the reason I would like to get deeper into it. So I searched some details about it, so I know, that each particle emits specific "rainbow" after it receives some amount of radiation from light in various wave lengths and similar situation...

Dear Forum, I'd like to talk about the formulas about aerodynamic calculations. Let's focus on the lift force. As you may know, the lift force is computed as The CL coefficient can be decomposed with a Taylor serie which is Now, each coefficient can be rewritten in detail as: As we can see...

Hey all, I'm either overthinking it or too tired but this problem should be an easy one to figure out but I'm stumped embarrassingly. Say in the photo above is a lever arm. I'm trying to backtrack to calculate the force a user must input (yellow) against a force (red). It can pivot around...

I've seen this question in a textbook Calculate the following commutator [[AB,iℏ], A] I'm not to sure how you go about it i know [A,B] = AB-BA

TL;DR Summary: A current pulse of amplitude I is applied to a parallel RC combination, plot to scale waveforms of the current ic for the cases a.tp < RC b. tp = RC c. tp > RC Are the calculations and waveforms correct?

I'd like to calculate the whole structure including welded beams and then calculate rails and the beam used for suspend a robotic arm. The problem is I've no idea how could I start. I was trying to find some training materials (mainly books) on this topic (design of supporting structures for...

Hello all, For a project I really need to know some number i can't seem to produce myself. we are flashing water @75 degrees Celsius, the water after flash-cooling is 67 degrees constant pressure is 0.27 bar (absolute) flow rate is 15000 KG/per hour. how much water is vaporized? Help is much...

This has been discussed in a previous thread https://www.physicsforums.com/threads/efficiency-of-two-carnot-engines-in-series.173879/ Th conventional answer is that the series efficiency is the same as one engine running between T max and T min but I am skeptical. I have attached my...

For this problem, Distance from objective to object ##𝑑𝑂 = 10.6cm## Distance between the objective and eyepiece ##𝐷 = 34cm## For (b) I got ##d_I = 26 cm## and ##M_1 = -2.4## which means that firsts image is inverted and real For (c) I got ##dI' = 35 cm## and ##M_2 = -1.3##. However, I...

Hello all! I hope I have come to the right place, and I appreciate any help! My first disclaimer is that I am not a math professional of any sort, I am not bad at it but I just wanted to start with that so if I ask a stupid question, it's because I am ignorant mostly. What I work in is risk...

My question is specifically with calculating the intensity. The book solution is I=P/(4*pi*r^2) but would this not give me a weaker electrical amplitude in the final calculation after plugging it in to I=(1/2)*√(ε0/μ0)*(E02) ?

##\require{physics}## Recently, I wet my feet in X-ray diffraction a bit more than what is usually covered in standard solid state physics textbooks at the undergrad level, like Kittel. Two good books that I chanced upon included Christopher Hammond, The Basics of Crystallography and Diffraction...

How do I go about the calculations for an air conveyor that has the same working principle as an air hockey table? The conveyor should not he bulky seeing as it is a prototype. Please help me.

Looking through the Art of Electronics, I barely see any equations, mostly description. However, checking out this video, we get a whole page of calculations. Are the authors of AoE expecting that practitioners are already fluent in these design calculations? Are there examples of such...

Hi. I wrote a little algorithm that calculates some physics equations for education purposes and it's in C++. I'd like to make it avaiable by creating a website and put that code in it so it either interprets the C++ code or preferrably works with an executable (but then how would it be...

I'm designing a lifting tool for a bar with a flared head. The bar is say 10m long and 10mm in diameter with a head on the top that is 20mm in diameter and 10mm thick. There is a fillet from the head to the bar of 2mm (for reducing stress concentrations). The bar will be lifted vertically and...

Hello, everyone I am now working on this project quite a while now and I just wanted to share it with this forum, which I was a member for a long time. I am working on a python application about GR and I believe I managed to create a very user-friendly layout. It's called GTRPy, and it allows...

I'm sorry I'm uploading lots of images because I don't know how to write equations here. PROBLEM DESCRIPTION I have to solve this problem: Figure P3.6: MY SOLUTION I did this: THE CORRECTION I got this as a correction: - Don't use the middle line in figure P3.6 in my calculations. -...

Im prototyping a machine to lower liquid from a height using a chains and sprockets. Essentially liquid will fill at top, be lowered over a distance of 4.8 metres then emptied at bottom. The liquid needs to be lowered at a slow pace due to resistance on the output shaft, I am considering...

[FONT=Calibri]Assuming the Sun’s core has a mass of 0.35 Msolar_mass and taking values for other quantities from a internet background search or from the following figures (i.e.: Radius "solar core" = 0.25 Rsolar_radius ): ------------------------------------------------------------------------...

Hi! I know this may seem like a silly question but I really just want to make sure I understand this correctly. I've already calculated the minimum and maximum values for time and height: t min = 0.58 s t max = 0.68 s y min = 1.98 m y max = 2.02 m To calculate the minimum average speed, would...

Hi, I'm building a rolling mill for flattening out bits of steel and I'm trying to make sure it's not going to break. I know that with a 1500w motor geared down to 60rpm (2pi rad/s) i end up with 239Nm of torque. 239Nm working at a radius of 0.0375m gives 6369N of force generated at the edge...

So far I have determined the evacuation time, a basic heat transfer between the heating element and plastic sheet, and a hold down force of the forming bed.

I'm wonder how one could calculate the total mega pascals total mega pascals that can be applied to a spinning flywheel before it exceeds its tensile strength example: a cast iron flywheel is spinning at 10,000rpm(Tangential velocity = 104.72) it has a radius of 100mm and a weight of 500g...

I want to compare my tight binding results with DFT calculation. Which one GGA or G0W0 is more trustable to compare?

I am trying to calculate the force required to lift/move the beam clockwise from the shown position. I have a force (F1) acting at the end of the beam, 5,000lbs pushing to the left, as shown. What is "Fcyl", or the force required by the cylinder to life the beam with the acting load, and rotate...

I would like to know the opinions on the paper that I saw about Michelson-Morley experiment. Michelson-Morley experiment was done in 1887 and had an impact on the future direction of physics. It is taught in schools as an experiment that proves the non-existence of the aether and proves the...

Me again! For a sci-fi story I'm working on, I've created a sci-fi technology called an Aneutronic Triple Alpha Fusion Reactor. It works via aneutronic fusion, in this case, fusing Deuterium with Helium 3, but it also mimics the triple alpha process found within stars to maximise fuel use...

Hi all, I'm writing a technical manual for a starship in a science-fiction series I'm working on, I wanted to check with some folks here to make sure my calculations are correct concerning the ship's engine thrust. The ship has a fully-loaded mass of 5 million metric tons. Using its...

Please tell me if I need to post my solution for this.., but I just have a question more or less 'conceptual' question about (c). so I know that from Newton's 2nd law for centripetal acceleration --> ##F_{rope} - mgcos(\theta) = ma_n## where ##a_n = \frac {v^2}{R}## such that where the normal...

Answer: I already found the answer for Sin theta 2 like the pic below But, I am still not sure about how to derive delta here. Can anyone show me they way? thank you

First, consider modulo ## 9 ##. Then ## 9\mid (5+1+8+4+0)\implies 9\mid 18\implies 9\mid 51840 ##. Since ## 51840\cdot 273581=1418243\chi 040 ##, it follows that ## 9\mid 1418243\chi 040 ##. This means ## 9\mid (1+4+1+8+2+4+3+\chi+0+4+0)\implies 9\mid (27+\chi)\implies 9\mid\chi ##. Thus ##...

Hello, I am trying to figure out if the investment into a watercooling system in a Cosplay suit would be worth it. I plan on using a water loop made by taking a "CoolShirt" https://coolshirt.com/product/white-coolwater-shirt/ and running water through it either from an ice bath in a sealed...

Current drawn by motor = ##\frac{120-75}{90}## = 0.5 Amps The answer says the power output of the motor is 37.5 Watts. The only way I can get that answer is if P = IV = 0.5(75) = 37.5. This implies that in an electric motor, the back emf is the voltage of the motor. This confuses me because...

I was having a conversation with a coworker and this question came up: is there a program like ORIGEN (or maybe even ORIGEN) to run decay calculations in reverse? It's a relatively easy process to start with a given quantity of an isotope (e.g. U236), run it through a program such as ORIGEN...

My question relates mainly to mechncial engineering but I guess the general principle may apply elsewhere. Up until now I have mainly been an engineer on the customer side (marine and offshore) , reviewing contractor reports, "sense checking" them and general engineering firefighting and...

Hello, I am interested in making an RC plane as illustrated. Some questions: 1. Given that the build material of the plane will be 3d printed out of PLA and I want the wingspan to be between 1.2m - 1.35m ideally. How can I calculate the minimum wingspan/wing shape/wing area to carry a payload...

The 4 level system categorizes international destinations at a level four if the 28 day infection rate per 100,000 > 500. The population of Costa Rica is 5,094,000. The WHO had 5,488 infections for 2/11/2022. How would you calculate the infection rate per 100,000? 5,094,000 ÷ 100,000 = 51...

I'm already confused by the terms circular, angular and radial. I've read the definitions but I'm still confused. What is the difference? Is ω the right symbol for frequency that I used? Any tips much appreciated!

How can one maximise one's confidence in the results of a theoretical calculation? After long and fiddly calculations I often encounter an uneasy feeling where I find it difficult to confirm whether the fruits of all that labour are actually correct. The first ports of call are always: -...

Hi, does anyone know how to calculate the current spring constant of a variable pitch spring when under compression. Since some of its coils get inactive when compressed the stiffness is increasing and consequently “k” is changing as well, is there an equation I can use to calculate the new...

My current project involves constructing an air bubble system to protect stationary docks from ice heave or ice jacking during the winter months. Ice jacking is the vertical lift as ice expands. When this grabs piles supporting stationary docks, it can wreak havoc. I am mainly confused as to...

I need an expert to verify equations about the coefficient of kinetic friction.

Given the following input parameters: Parameter Value Rs (Resistance through stator) 1.4 Ω Rr (Resistance through stator) 0.7 Ω Ls (stator inductance) = Lr (rotor inductance) 0.002 H xs = xr = 2*π*f*Ls 0.6283i Ω Lm(magnetic inductance) 0.01 H xm = 2*π*f*Lm 3.1415iΩ f (frequency)...