Calculations Definition and 982 Threads

I searched a lot of google for calculations on eddy currents, and got a lot of things that describe how eddy currents work, but almost nothing about how to quantify the induced currents and the resulting magnetic field. Does anyone here know much about where to start? In particular, I'm...

Horizontal water rocket thrust calculations - HELP! Hi All, I want to accelerate a 90kg body at a rate of 2 m/s2 for a period of 1 second using thrust developed from a number of water bottle rocket jets. Based on the drag coeff calculated I believe I need to develop 190N of force. A...

Hi, I'm right now coursing IB (equivalent to A-levels) and one of the compulsory essays we must do is called Extended Essay. It's an essay you do on a topic you choose. I choose aerodynamics. Created a "wind tunnel" out of plastic and made it rigid with hard plastic pieces which were partially...

This is an issue I am running into at the beginning of my physics course. Homework Statement Given distance and time in minutes, calculate the time in hours (part of a larger average velocity question) and graph over 170minutes. Include error bars in the graph Homework Equations...

I just bought a new car, nothing incredibly special. And being a nerd, I love creating theoretical calculations based on given data. So, I've been trying to predict the effects on my car under certain scenarios. I am doing my best to figure out the effects based of equations alone, and not...

Given 2 vectors, say x and y with a relationship of barXx-barYy (barX =1,0,0 and barY=0,1,0) calculations for the vector field in x and y plane are: Magnitude = sqrt(x2+y2) tails of vectors begin at input points (IE: if I choose 1,0 or 0,-1 etc) and the magnitudes are calcluated from these...

My problem: I calculate, using Differential Geometry, the surface area of a specific part to be 50% more than the surface area AutoCAD calculates it to be using the AREA command on an extruded solid. I am certain that my calculations are correct. I use theorems of Differential Geometry that...

To this shape http://img10.imageshack.us/img10/2301/nocalculations.jpg Uploaded with ImageShack.us I'm asked to calculate the estimate of the static moment of inertia of the planar shape towards the x axis, that goes through its center of gravity. And then I'm told that I'm asked for...

Homework Statement The task is to show the invariance of a given Lagrangian (http://www.fysast.uu.se/~leupold/qft-2011/tasks.pdf" ), but my problem is just in one step (which i got from Peskin & Schröder, page 70) which i can not reproduce due to my lack of knowledge regarding spinors. The...

The ourput Noise Power is given as No = kTsBG + kTeBG ...= k.(Ts+Te).B.G But when it is asked in dB or dBm, How to calculate it something like 10Log10(Value) or 20Log10(Value)

Hi guys/gals, First post here - in need of some desperate last minute help. Today is my last day to study and I will have my final exam tommorow. I've been doing past papers all day, and there a few questions I have no idea/never seen before in my course material. Part (c) I have no idea what...

Here's a practice diploma question I found on the internet, this isn't homework. I'm studying, I just need help on how to do this type of question. http://www.paulway.com/physics30/p30dips/p30jan2002.pdf (Page 11 Numerical Response #5) Answer: 4.80x10^-3 Homework Statement In the magnetic...

I'm working as an intern at a factory that produces refractory bricks, mainly doing measurements on a tunnel kiln they use for firing the bricks. The bricks are heated with several natural gas burners in a firing zone. To determine the required air for both stoichiometric and excess-air burning...

A star is 40 light years from Earth. (a) How far would you measure this distance to be if you traveled it in a spaceship moving at 1.00X10^8 m/s (b) How long would the trip last (for you)? Can someone please help me out with this question and what equations I should use to solve this...

A rectangular plate has a length of (21.3\pm0.2) cm and a width of (9.80\pm 0.1) cm. Find the area of the plate and the uncertainty in the calculated area. Solution Area = lw = (21.3\pm0.2 cm) X (9.80\pm0.1 cm) \cong(21.3 X 9.80 \pm 21.3 X 0.1 \pm 0.2 X 9.80) cm^2...

So I've never gotten a straight answer as to how you calculate the resistance of a coil (or cap for that matter). I hesitate to use the term "impedance" because I've been told too many times to count that impedance is the total resistance of a circuit. My professors dance around the topic from...

Homework Statement If ⎮v⎮=2, ⎮w⎮=3, and the angle between v and w is [tex]\pi/3[\tex], find ⎮v-2w⎮. Homework Equations Im not sure how to go about this. maybe use [tex]\cos\theta[\tex]=u∙v/⎮u⎮⎮v⎮ The Attempt at a Solution i'm not sure where to start. i know this has to be pretty...

Hello everyone, sorry if this is posted in the wrong section; I just signed up. Homework Statement Okay, so the question in my textbook is: "A car engine needs 1000W to start it. The starter motor supplies this power. The starter motor is 80% efficient and it runs off a 12V battery. a)...

I have to come up with an experiment using cardboard boomerangs that the rest of the class will do. The class then has to make calculations and test out the boomerangs to see if their calculations were correct. However, i don't know what kind of experiment I can have the class do with...

Homework Statement An oil drop whose mass is 3.30x10-15kg moves at a constant speed of 1.70m/s upward between two horizontal parallel plates. The plates are 1.00cm apart and are connected to a 6.75x102V battery. If the oil drop is negative and the top plate is positive, calculate the number of...

hi, I'm running some calculations in the background of my Linux work computer, and I now have some more jobs for it to do, but the current calculations are not yet finished. For example, my new file, RUN.in has the following: ./cal1 ./cal2 ./cal3 ./etc and this is similar to what I have...

I was wondering if I do an IRC calculation and the energy range of the IRC does not quite reach the energy of the reactant or product of the system, do I need to make the IRC calculation "wider" (i.e. go more forward and reverse) so that I can interpolate the reaction coordinate of the system...

Homework Statement http://img217.imageshack.us/img217/654/circuit05.jpg Internal Resistance = 10 ohms (each) RL = 20 ohms R2 = 30 ohms R1 = 50 ohmsA) When the switch is open, calculate I B) When the switch is closed, calculate I Homework EquationsThe Attempt at a Solution First I'll try to...

On p 51 of these notes: http://www.damtp.cam.ac.uk/user/ho/Notes.pdf , I'm trying to follow the calculation \int \frac{d^dk}{(2 \pi )^d} \frac{1}{(k^2+m^2)^2}= - \frac{\partial}{\partial m^2} \dots It looks to me like we can just use the calculation above and then take the derivative at the...

1. At 10°C, 32 g of water is mixed with 430 g of ice at -5°C. (The heat capacity of water is 4190 J/(kg * °C), that of ice is 2090 J/ (kg *°C), and the heat of fusion of water is 3.34 * 10^5 J/kg) a) What mass of water freezes ? b) What is the change in entropy of the system? What I did on...

1.nitric acid reacts with potassium carbonate according to the following reaction 2(HNO3) + k2CO3 ----> 2(KNO3) + H2O + CO2 if nitric acid is reacted with 50.0 g of potassium carbonate, find the mass of water produced 2. manganese is added to steel to increase strength and resistance to...

Homework Statement For our final project we have to design a lab, take the data, and write a lab report. My lab is bouncing balls of different masses, onto different surfaces, from different heights, and use balls of different materials in order to see what factor influences efficiency the...

Homework Statement For our final project we have to design a lab, take the data, and write a lab report. My lab is bouncing balls of different masses, onto different surfaces, from different heights, and use balls of different materials in order to see what factor influences efficiency the...

So in a question I have to find out what's the "max power" that can be spread around a circuit without causing any damage to the resistor. So, unsure what "max power" means, I googled "max power" and ended up with many images and resources of Homer Simpson, half naked girls and cars, with no...

Can someone please explain how kg x kg-2 (in superscript) can equal kg? I hope it does or my calc is wrong! Anywhere I can revise this kind of thing? Mick

Hi guys I am doing this question out of a book, the answer is not given so I am trying to find out if my answer is correct or not. Please find the attached image which shows the question. 1) For the reaction in Question (a) I found the reaction (Ry) to be 220 kN. Rx = 0 because there is no...

Hello all, just a little centre of gravity question: A 1.7m long barbell has a 20kg weight attached on its left end and a 35kg weight on its right end. a) If you ignore the weight of the bar itself, how far would from the left of the barbell is the centre of gravity - I had no trouble...

Hello all. I'm trying to figure out how to determine the correct sign of paths and surfaces defined for calculating quantities in electromagnetic problems. For example, say there's a wire in the shape of a rectangular prism along the z-axis with some current density, \vec{J} . Then the...

I have never really studied the heavy side of electrical engineering. We are currently running a machine that runs off 3 phase supply. I want to measure the kW or KVAh on this machine using a CT which is all already set up. The Current at maximum on 1 phase reads at about 130A, and the phases...

Homework Statement I'm in a physics 2 (electricity and magnetism) course, and I'm having trouble with something the professor discussed in class. I tried approaching him about it afterwards, but it still didn't make sense to me. I really think he made a mistake here, and I'd like input...

Hi Guys hope u r feeling good i just finished my catapult project and the problem is that i have only two given and the problem is that i have only two given values the \Delta T = 1.1 sec.\Delta_{d}x=2.2 m , and the angle is 70' degrees. and nothing else. http://tinypic.com/r/2ylqpux/7 i...

Hi Guys, So I am biting off more than I can chew with my latest project.. and looking for help. I am going to fabricate a kit car chassis, The suggested material is 1' x 1' steel box section but why? Could anybody help by suggesting the kind of calculations I would have to research...

The template doesn't really work well for mine considering its a lab sorry ><. I am quite confused on how to do the calculations on my chemistry lab, i have scanned, and rewritten my answers so they would be more clear :-) . the questions i have are on the 3rd and 4th image, I am just really not...

Thank you <3

A transverse wave is described by the expression y= 0.05cos(4.19x-1260t). You may assume all measurements are in the correct SI units. A) What is the amplitude of this wave? B) What is the wavelength of this wave? C) How fast is the wave travelling? D) What is the maximum tranverse velocity of...

Problem: An electron enters an external magnetic field in the same direction as the field. Explain what happens to motion of the electron while in the field. I predicted the electron to stay still, since the angle between the direction of speed and external magnetic field is 0. can anyone...

I would think someone would have thought about this already, I'm not taking physics so forgive my assumptions about water flow, thrust etc. but, If I were to say... take a 12" I.D. 24" section of PVC Pipe filled about 85% of the way, 6^2*3.14*24/231*.85 = so about 10 gallons, 80 pounds of water...

So, we learned that the units of Moment of Inertia are mm^4. My question is how do they use moment of inertia in static calculation (where we use Newtons), if Moment of Inertia is in mm^4?

You can try Good Tool for simple calculations at the URL: http://www.formula-gate.com/converter-calculator/math/equation-calculator.aspx

Hi I wasn't sure whether this is technically homework or not but anyway. I am building a miniature wind turbine for a basic project just for myself. I was wondering if there was anyway for working out the voltage gained from the generator. I know this could be gained from using P = IV but...

Can someone explain to me how XFoil calculates the Reynolds Number for computational analysis. I have the XFoil manual which explains the method used in calculating the Reynolds Number. But what I don't understand is that it says that the "Reynolds Number is defined with the freestream velocity...

there is a car crash where car A is resting at the traffic lights and car B is driving at 100km/hr and at 45m saw the car and stepped on the brakes. the velocity of car B is 27.8m/s the deceleration is -6.7 m s^-2 the thinking distance is 41.7m weight of car B is 1385 kg weight of car...

Hi, I am currently taking a college-level Physics course and ran into some troubling questions regarding significant figures. I wasn’t sure which forum I should post this to but the math forum seemed like the most adequate one. So here goes… I have no problem understanding the basic rules for...

Homework Statement A 7.5 kg box is being lifted by means of a light rope that is threaded through a single, light, frictionless pulley that is attached to the ceiling. a) If the box is being lifted at a constant speed of 2.0 m/s, what is the power delivered by the person pulling on the...

For the V Graph upload: It asks to: The graph shows the motion of a stone thrown vertically upwards. Calculate the maximum height reached by the stone: a) by first finding the average velocity of the stone b) by finding the area under the graph for a) I did total displacement / total time =...