Loss Definition and 841 Threads

Hi, I have been trying to understand eddy current loss in transformer cores but seem to have run into a bit of a misunderstanding with one of the books I have read, and I was wondering if someone could just clarify if I have got this all right. starting with the beginning, if the magnetic...

How many watts would you need to keep a 64oz bottle of water at 40 degrees when the temperature surrounding the bottle is 10 degrees (that's assuming you don't take into account surface area) ? How many btus if you took into account the surface area of a 64oz soda bottle ? What I did...

Homework Statement Calculate the insertion loss for the network in the diagram? Homework Equations 20log(N)dB N = R0 + R1 / R0 - R1 The Attempt at a Solution N = R0 + R1 / R0 - R1 N = 141.42 + 100 / 141.42 - 100 N = 241.42 / 41.42...

Dumb question, but something I don't get. I see this expressed in many basic examples of what voltage is. You have 1 object that has too many electrons and 1 object has too little. The potential difference between them is what is expressed as/in volts. If you connect a conductive wire...

Homework Statement If only conductive heat loss was significant for a house, then by what percentage would you lower the heat loss if the temperature was reduced inside from 70°F to 68°F, when the outside temperature is 26°F? (Hint: Try using a ratio.) Homework Equations N/A, use a...

I am building a mathematical model of a piston engine which calculates the pressure and temperature of the cylinder gas every 1° of crank angle. I'm having some difficulty with the heat transfer to and from the cylinder wall (to when the Tg > Tw and from when Tg < Tw). I found the heat...

Hi, The evolution of a close binary is driven by angular momentum loss to gravitational radiation, so that (dJ/dt)/J = -(32G^3 M1*M2*(M1 + M2))/5*(c^5)* a^4 From relations mass-radius, (-dM2/dt)/M2 = -(dJ/dt)/J / (4/3 - q) and R2/a = ((M2)/(M1 + M2))^(1/3)* (0.462) M2 =...

I'm struggling to understand the implications and origins of the 2nd law. Entropy is such a slippery subject. Wikipedia has many many definitions of entropy. I've been studying Professor Susskind physics lectures, so I'm most interested in his favorite definition: that information is...

Howdy everyone, I'm sorry if this is in the wrong forum, but since I believe it is mostly a thermodynamics problem I think this is the right arena. My questions stems from trying to insulate a bank of batteries in cold weather. I am trying to determine the proper material and design...

http://www.theguardian.com/film/2013/sep/05/jack-nicholson-retires-memory-loss Sound like it's possibly more serious than an aging memory. It surprises me because The Departed was just on TV a few nights ago and I happened to see it for the first time. This was released in 2006, just 6 years...

Hi all. I'm starting my college apps and started with MIT. Here's the prompt: "Tell us about the most significant challenge you've faced or something important that didn't go according to plan. How did you manage the situation?(*) (200-250 words)." Below is my response. What I want to know...

Homework Statement A particle of mass ##m_1## experienced a perfectly elastic collision with a stationary particle of mass ##m_2##. What fraction of the kinetic energy does the striking particle lose, if it recoils at right angles to its original motion direction. (Ans: ##2m_1/(m_1+m_2)## )...

Here is the question: I have posted a link there to this topic so the OP can see my work.

Mars current atmosphere is 0.006 bar. It is theorized that the atmosphere was thicker in the past possibly thicker than Earths 1 bar atmosphere. There are many processes that could have done this such as having no magnetic field, lack of geological activity, a planetoid crashing into it and...

Marketed to stop menopausal hair loss, has it been shown to be effective? http://www.plantur39.ca/en/

If I throw a ball vertically upwards from the surface of the earth, the upward motion slows due to gravity. At the ball's highest point, I have placed a repositioned platform for the ball to rest on; so it sits motionless, perched above the surface of the earth. When the ball began it's...

Dear all, Please tell me the steps are used to find Modal loss factor of composite constrained layer damped beam by using Finite Element software such as ANSYS etc.

Hello, In a MOS capacitor or MIS after applying a voltage on the metal, the valence band and the conduction band bend downwards (in the usual band diagram) when a positive voltage is applied. (p-type semiconductor). When the voltage is large enough, electrons forms an inverse layer(green)...

1. Homework Statement a) Calculate the theoretical diameter of pipe, nominal pipe diameter and mean velocity of nominal pipe diameter. Maximum velocity = 1.8m/s Q(vol. flow rate) = 0.01M^3-1 b) Find the Reynolds number for the process and then the head loss due to friction, state any...

A single photon approaches a polarization filter. It's orientation is described by a probability amplitude wave function. It is not reflected or absorbed, but passes through the filter. Now it's orientation immediately after is definitely known. Question 1: is there no...

Homework Statement I have a manufacturing plant, and I know the material/thickness of every wall and the roof. I want to estimate the plant as an empty box, where I know the surface area of each material surrounding the box (ex. 4000 sq ft concrete, 1000 sq ft of windows, 1000 sq ft of xyz...

I am new to the forum. I was calculating the force losses in a seat belt pretensioner. Here is the question. A cylindrical plastic rod is pushed on one side at a force of 6367.2 N inside a metal tube. Find the energy loss (force loss or final force or output force) due to the compression of...

Homework Statement Share market trading calculator. I have tried to write code to calculate the buy and sell with profit/loss on historical data using moving averages. I'm am not interested in leverage yet. bank = 10000 equity = 10000 sell = is current price of an instrument on the...

I found this sizing chart for ventilation ducts. Notice the gray area for what I suppose is the accepted pressure loss area. What I wonder is why it changes as the sizes pass Ø800. From here on the upper pressure loss limit goes down to 0,7 Pa/m. Is this because of velocity issues or something else?

I'm looking for the general formula for Angular Momentum radiated away from quadrupolar electromagnetic radiation. I searched the usual books (Jackson, Landau-Lifchitz, ...) and just found the usual dipolar contributions. Using dimensional analysis and energy radiated away, I found this...

Hi, i just perfomed a differential distillation experiment, the initial solution cointaned ethanol-water solution with 4.9% in mass it weighted 399.63g Water Mass:381.25 Ethanol Mass:19.96 We distilliled the solution for 20 minutes and obtained two solutions, the distilled had 35.87g and the...

When we have ethanol on our skin it feels colder than when we have water on our skin. The explanation given was that more energy is required to turn one molecule of liquid ethanol to gaseous ethanol than for one molecule of liquid water. However, in that case won't more of the water evaporate...

Hi all, it might be a silly question, but my math is "a bit" rusty. I want to find the equation of the volume lost during the dissolution of a sphere particle as function of time: A=area of sphere V=volume of sphere t=time k=dissolution rate as volume dissolved over area time...

Hi guyss~ I need some help for one of my assignment about heat loss from a cone shape fin as we can see through the picture I've attached with this thread. Looking forward to all of your answers

I have a friend who told me they are interested in this new weight loss product. I am always highly skeptical of such products, but the friend said she knows someone who lost 6lbs in two weeks without changing anything else. Anything in here that looks promising or is this more fools...

Homework Statement A trolley is of mass 20kg is pushed 35 metres up an inclined plane (to a height of 10m above ground level). The inclined plane is at arcsin(2/7) to the horizontal. A 100N force pushes the trolley to the top of the plane, the force being parallel to the inclined plane. The...

Homework Statement I am working on a project where I have to design and size an aquifer. There are two which either store hot or cold water for 6 months which is then pumped up to be used in either the summer or winter. The aquifer is going to be 80 meters under the ground. The rest is...

Hey! I need to calculate the flow pressure drop inside a two dimensional diffuser (please see image below). The average flow velocity at the inlet is 0.095 m/s. The fluid is air at a temperature T=373K . I can't find any close model at any fluid dynamics handbook. Does anyone know how can I...

I work for a manufacturing company. We want to make some improvements to our compressed air system, but we want to establish a baseline of our current efficiency for cost justifications, etc. One planned improvement, is redesigning our current piping layout. We spoke with a consultant who wants...

I have an Altronix AL600ULX power supply which will output 24VDC and is rated for a maximum of 6A. I want to have this power supply activate a locking mechanism which is located several hundred feet away. I have already purchased 18AWG cable to connect the locking mechanism to the power...

Homework Statement On a clear night the Earth loses heat according the equation \frac{dQ}{dt} = \sigmaAT4 If the average temperature of the ground is 10°C, calculate the rate of heat loss, per square metre, by the Earth and the total heat lost, per square metre, in one hour. Homework...

Greetings All, I have a question regarding Pressure Loss through a Small hole vs Time. My simplified scenario is that I have a vessel filled with Sea Water Pressured up to 70 bar. At the outlet valve, there is a pressure release port of 5mm dia which is able to relieve the pressure down...

Problem: The fission of ^{235}_{92}U releases approximately 200 MeV. What percentages of the orginal mass of ^{235}_{92}U + n disappears? Solution: Using E=mc^2 we can estimate the amount of mass m converted into energy E. Solving for m we get, m=E/c^2=[(2 x 10^8 eV)(1.60 x 10^-19...

Could someone please check my answers so far for this question as its getting very messy so I'm not sure if I've made a mistake :/ Two particles of masses 2m and m are moving along the x−axis with constant velocities u1i and u2i respectively...

Homework Statement Show that the exponential distribution has the memory loss property. Homework Equations f_T(t) = \frac{1}{\beta}e^{-t/\beta} The memory loss property exists if we can show that P(X>s_1+s_2|X>s_1) = P(X>s_2) Where...

Does a DC transmission line for a given amount of power, do better at higher voltage? I know power is the product of the Voltage and current. The logic given to me by one of my peers was that I2R losses are less if the current is low. And so for a given power, it would imply V to be higher...

http://www1.gantep.edu.tr/~physics/media/kunena/attachments/382/chapter2.pdf On page 9 and 10 of the above PDF the method for deriving the fractional energy loss per cycle in a lightly damped oscillator is described. I understand and follow this derivation. What would the derivation...

Homework Statement Hey everyone, trying to finish up a report and having a problem with getting to the final answer. It is a final report on hydro kinetic energy. We are planning to install a hydro kinetic turbine under a bridge and calculate what the energy output would be in KW. I am...

Firstly my knowledge of science is armchair tv level so any overly complicated explanations will be lost on me. What is going on it terms energy conservation with the casimir effect. As I understand it virtual particles created outside the plates have a greater range of wavelengths than...

Hello All, I am playing with some questions in an old textbook I have been reading through and I am getting confused on this question regarding GM Tubes.The question that is stumping me goes like this: If a certain GM Tube has a time constant of 80msecs and procedures require that...

Homework Statement here the situation, i have a straight pipe with a spheroid-like shape placed in the middle which is supported by two supports. I would like to calculate the csa of the spheroid section using 50 iterations but i am finding it difficult to calculate. link...

Homework Statement In Australia, New South Wale's final year of high school, a common question is asking something like: How does distributing electricity at high voltages reduce power loss in the transmission lines.Homework Equations P = VI = (I^2)R = (V^2)/R. Not very clear without...

Hello, I am studying transformers now for the exam and I came across this question. It made a confusion in my mind. I took the photo of the question and put it into attachment. The answers B and C looks very similar to each other and in my humble opinion both of them are true. I would be...

Homework Statement Given the reaction: 2LiHCO_3 + SiO_2 \rightarrow Li_{2}CO_3 + SiO_2 + CO_2 + H_{2}O where SiO_2 is unaffected, the mass of the 2LiHCO_3 + SiO_2 is 9.62 g. and Li_{2}CO_3 + SiO_2 is 6.85 g., find: a) mass loss due to CO_2 + H_{2}O b) mass of LiHCO_3 in the original...

Hello all, Considering that Einstein told us that E=mc2, that means that any energy is generated at a cost of mass loss? to be more specific: When a power plant generates energy by burning gas or coal, a part of the particles in the fuel burned simply disappear and can't be found in the...