Calculations Definition and 983 Threads

Homework Statement Calculate the complex power delivered by the source V = 12cos(wt) V Homework Equations V = IR The Attempt at a Solution 1. I combined 8ohm resistor and 8j ohm inductor in parallel to get 4+4j ohms 2. I combined that with 4ohm resistor in series to get a Zth of 8+4j ohms 3...

I have a model venturi I've created useing a air compressor letting the compressed air out of a small nozzle at the end of the air hose attached to the compressor. The nozzle is placed within a pipe causing the release of air directly torward the right of the pipe then to atmosphere leaving very...

Homework Statement What will the new amplitude be if A=.117m and the mass is 0.1kg. The spring constant is 3.587N/m and the mass is then doubled. What is the new velocity max? What is the acceleration max? Homework Equations Fnet= -kx, vmax=A(ω), ω= √k/m The Attempt at a Solution...

I have some questions about the first discovery paper that was released about gravitational waves, especially some of the maths. How did they: 1. Calculate the masses of the black holes that merged 2. Calculate the energy radiated away in gravitational waves 3. Calculate how far away the event...

Homework Statement I have to do a calculation in electronvolt, using physical constants. The final result must be in electronvolts. I can grab the physical constant from scipy (python library). How do I know which constants I can keep in SI units, and which constants I have to transform...

Homework Statement If a 5 amp unit can cool 4 cups of water from 75 to 50 degrees fahrenheit in one hour, what temperature could a 30 amp unit cool 128 cups of water in the same amount of time? Is there enough information here to get an idea about what the 30 amp unit would do? If so where...

Hello friends, today i have this question about precision. Actually I'm trying to do a simple use of the pow function for a small number x=0.005 squared. By entrying pow ( x, 2) my console does not output the proper number 0.000025, but some memory error. I've read about it and i may be able to...

Say I have got a super cooled cylinder of half hydrogen and half helium. This cylinder has a pressure of 100,000 Pascal's. At this pressure, hydrogen boils at 20 Kelvin and helium at 4.21 Kelvin. I hope to separate helium by cooling gas down to 4.21 Kelvin but I know that even at the...

Hi guys, I need help with heat transfer calculations The scenario is : Installing a coil around a hot pipe and extract the heat from the hot pipe to heat the fluid flowing through the coil. The whole assembly is insulated. I need methods/formulas to calculate the amount of heat transferred so...

Hi I am here asking for some help. I simply struggle with maths due to ahead injury sustained in a motor accident. I am trying to find out the forces that I suffered in the crash. I know from software forums people do not like doing other peoples homework, instead the goal is to help others...

How can I calculate power and torque requirements for a device resembling a wheelbarrow using 12v battery and motor/gearbox drive?

Hello, I do want to make a small sprinkler for my garden. As you can see it is a simple tube with one end sealed and the other end will be attached to the water hose. Now what I want to do is drill a couple holes to the sides of the tube and get a sprinkler like that. I would like to know how...

i am a physicist now i am doing Ms in nuclear engineering ... i need to understand basic concepts ... neutron transport equation ? what is the transport phenomenon actually ? and pressure drop calculations in core ... please help thanks in advance

So i have this Diesel Water pump, i need to achive a pressure of 4 bars at the end of the hose, How to calculate the pressure in inlet to achieve the desired result of 4 bars at outlet. (Assuming that I'm using a standard hose of length 30metres, with a diameter of 2.5 inches) Pump FLOW RATE IS...

Hi guys and girls! Here's a hard one I need help wit. I really want it resolved because I sincerely love it. There's an aerodynamic phenomenon called 'the Vulcan howl'. Example: It occurs when engines are employed at maximum power or more (maximum power in aircraft is only a recommended...

Please can someone tell me if this calculation is correct? Please see attached question. I have used the +/-3V as the saturation voltage and multiplied it by R2/R2+R3 to give me +/-1.5V.

When calculating the electric field from a point above a line of charge using coulomb's law, the integral that comes up is of the form \int { \frac { dx }{ { x }^{ 2 }+{ a }^{ 2 } } } . But if the point we were asked for is right in the middle, the horizontal (cosine) components cancel out...

Can someone tell me the mathematical and physics background i need to perform ab initio calculations to determine thermodynamic properties of materials. I am a Mechanical engineer with a masters in Metallurgy

This is my first question here. I tried my best to work out it by myself but it didn't work. I'm reading Computational Methods in Physics and Engineering by Samuel S M Wong recently. I don't know how to deduce Eq.(7-2) on page 299 of this book. There are some paragraphs on this page as...

Homework Statement I have attached a picture of the question. Homework Equations P = pgh The Attempt at a Solution I can calculate pressures in a barometer using the simple rule that at same height the pressure exerted by tubes is same. But the same rule seems not to imply in manometers...

Hi, that's my first post here.First of all – I do not want to ask someone to calculate something for me. I did my best (I hope correctly) – can you briefly check it and answer my additional questions? I am especially interested in these questions – I always have some doubts during calculations...

So if you were scuba diving and your depth gauge broke, could you create a system where you exhale some air and record the time it took to reach the surface. If so, what would they equation look like?

Homework Statement 1kg of water fills 151.1L of rigid container at pressure 2MPa. Then the container is cooled to 40C. What is the final pressure? Homework Equations Steam table properties. The Attempt at a Solution How can we know the pressure? I think it is wrong to assume that the specific...

Hi guys, not sure if this is the right place. Its to do with an electronic project I've been working on. However please point me somewhere else if you know anywhere better suited! (It is quite a long post sorry) Basically, I have created an LED array used for stimulating cells with light and I...

Homework Statement The maximum steam pressure by the turbineintake is 550 C. Based on available cooling water the pressure in the condensor will be 0,06bar the isentropic efficency is 80 %. Decide the steam pressure at the turbine intake if the steam content is at least 90 % We have struggled...

I am tasked to find the tensions of two wires by calculating the "magnitude of the vector" in a high school physics/precalc class. I have tried working out the equation in several ways but they all end up in an unsolvable format. So, in reference to the picture, A = 35 degrees, B= 30 degrees and...

Hi guys, Im trying to build an electric wheelchair with mecanum wheels, and as you might know, each of its 4 wheels has to be independently powered for the chair to have holonomic motion. With my desired speed to be around (brisk) walking speed only, say 1.15 m/s, and my mecanum wheels sized...

Homework Statement For the ALS logic circuit, estimate: (a) the current IOL (b) the delay in a 1-to-0 transition at one of the inputs of GATE 1 appearing as an effect at the output of GATE 5. (c) the total power consumed by the circuit in a quiescent state. Homework Equations /data[/B] The...

Yesterday, I made a thread about creating gears in Inventor. I successfully created them, but now I have a few questions regarding material strength. Background: I am making an autonomously rotating compost tumbler for an engineering class. The design consists of a drum surrounding an axle...

Dear All, Apologies if this question isn’t really in the right place. I wanted to check I’ve understood some data correctly. The link below shows lunar cycles all the way back to 2000 BC: http://astropixels.com/ephemeris/phasescat/phasescat.html. Suppose I click on a table and get a date of...

Hi, I'm doing a lab report and for every number we need to calculate the uncertainty. I tried to calculate by using the SQRT of the number but i didn't get the same answer as my partner had? could you help me! These are the numbers and the uncertainty of my partner which i could not figure out...

I have a code that loops through and does some computation on 5 random values from my lists of data (2187 rows long). for i = 1:3 randomdata = round(rand(5,1).*2187); xval = x(randomdata) yval = y(randomdata) numerator = length(xval).*nansum(xval.*yval) -...

Homework Statement A ¼ in. diameter rod must be machined on a lathe to a smaller diameter for use as a specimen in a tension test. The rod material is expected to break at a normal stress of 63,750 psi. If the tensile testing machine can apply no more than 925 lb of force to the specimen...

Homework Statement I need to calculate the work function of a photoemissive material. Light is shone through a photocathode (cathode) and the stopping potential V, is measured between anode (stainless steel) and cathode using a picoammeter) Following are the data measured/calculated ν = 1.402...

Hi, I am trying to do a comparison of electrical efficiencies between 2 HVAC compressors but struggling to find formulas or calculations to figure it out. Can anyone help me?

For my physics class, I did a mousetrap car and we were supposed to calculate some answer, and I would just like to know if I did my work right. Sorry, I know this is a lot of work. Homework Statement 1. Calculate your mousetrap car’s average speed. 2. Calculate the fastest velocity of your...

Hi I'm looking to design a 4 bar compound linkage. I know how torque, force, power and angular velocity are transferred on four bar mechanisms. Could someone help me with compound four bar calculations? http://i66.tinypic.com/2jg6z9t.jpg The lower arrow shoes the input torque. I need to design...

Homework Statement The bar, of length AB=2m, with a mass of 6.00 kg. There are two weights, let's call them m1 and m2, hanging off the bar. m1 is 4.4kg, at 0.66m from point A. m2 is 2.0 kg, at 1.84m. The bar is suspended by two spring scales defined as F1 and F2 (assuming negligible mass)...

Homework Statement Find the magnitude of an electric field intensity at a distance 12.9 cm, from the axis of a long, straight conductor, which has a radius 3.82 cm, and a charge density of 1.61 C/m. Homework Equations Gauss's law The Attempt at a Solution E= λ/2πrε0 Hello, I'm having some...

Homework Statement A permanent magnet DC motor has an armature resistance of 0.4 Ohms. When a voltage of 110 V is applied to the motor it reaches a steady-state speed of rotation of 126 rad/s and draws 39 A. (a) Find the power loss in the armature (b) the power input to the motor I really...

I am really, really stuck! I am trying to write java code to model the solar system, or at least currently just earth, the sun and mercury. I've made a big mistake somewhere, the planets are very unstable and either move in a line or spiral inwards! I just wanted to check that I'm doing things...

Homework Statement Soon astronomers will be imaging the “shadow” of light from the event horizons of black holes. Since black holes are very small, this achievement seems impossible. Nevertheless, it is possible for three reasons: 1. Supermassive black holes have large event horizons. 2. Radio...

Homework Statement Questions are attached to this thread. Homework Equations P =mv (P is momentum) P = F/A (P is pressure) F = deltaP/delta t (P is momentum) The Attempt at a Solution I have managed to do questions a-e which I was very happy with but then moving onto the extension has made me...

Hi, i am a student of bachelors of mechanical engg. (2nd year). I want to build a go cart. But i don't know the basics. I don't know a thing about automobiles. I am learning the catia software for designing. But i don't know what kind of "calculations for go cart" must be required to design the...

Hi,So honestly I suck at making Calculations in my mind, like guessing the result of 66 x 5 ! Does that indicate something about being bad at Mathematics ? Or it does not matter ?

Is there any method for how to choose k-points in band structure calculations for aluminium slab 5*5*4 can somebody help in this question? Thanks

Homework Statement At what energy will a non-relativistic calculation of the De Broglie wavelength of an electron be in error by 5%? What is this energy for a proton? Comment on your results. Homework Equations I have two (seemed to be) logical answers for this question, but with different...

Homework Statement A 178.0g ball is dropped from a height of 2.99m, bounces on a hard floor, and rebounds to a height of 1.36m. The impulse received from the floor is shown below. (Is a picture of a graph, Y-axis is force, X-axis is time. No numbers are labelled and is simply a line starting...

Hi all, As part of a school project, I'm attempting to demonstrate some sample calculations of a car radiator and I'm a little lost. I'd like to demonstrate some cooling requirements for the peak power output of my car engine: 325 horsepower at 4400 RPM. Can anyone offer any guidance as to...

First off - English isn't my native language, so please go easy on me if my translations are wrong. The problem: A ball with the mass 20g and the speed 3.0m/s collides with another ball with the mass 80g which is standing still. The collision is a sentral, fully elastic collision. Find the...