Loss Definition and 841 Threads

this is the formula for calculating core loss http://power.thayer.dartmouth.edu/pictures/function.jpg alpha, beta and k are constants that have to do with the material of the core. what are f and B, and what exactly does Pcore mean

can i solve for core loss of a cylindrical inductor by knowing the dimensions of it and the material it is made of?

In bomb calorimeter, when dry ice is added to warm water, the final mass of the inner cup and remaining water is less than the initial mass of the inner cup and water. The calorimeter did not decrease in mass so it means water is lost but not gone it just changes it state. The water was in...

I was watching a video on youtube and thought about how well dominoes transport energy from one place to another. As soon as you set off one, it seems like you should be able to knock over an infinite amount of dominoes, but could you really? How would you prove if the initial energy you put in...

Homework Statement Particle A with mass 2m and particle B with mass 5m move towards each other with speeds of 8u and 2u respectively on a smooth horizontal plane . After the collision , particle B moces with speed u in a direction opposite to that of the original direction . Find in terms of...

Hi, I am using a 3 phase BLDC Motor. The scenario is, "When anyone of the phases to the BLDC motor fails, the hardware will disable the particular phase. My software should stop firing that phase." Thereby the motor should run with only 2 phases. Is this practically possible to run a 3...

I want to build a small geothermal cooling unit to cool one small room in my house. If i lay 0.5" pex pipe which is 0.475" ID. The big question is how long does the water flowing in the pex tubing have to stay under ground. Constant ground temperature is about 55 degrees F around my house. I...

Homework Statement Alright so I am doing a fairly simple experiment testing how the temperature of water in a beaker effects how fast heat is lost. Have done the tests, but need to get some predicted results to compare them too. Have been using a glass beaker filled with 200ml of water...

Hello, I am working on making an Excel work book to aid in figuring out pressure drops in a system. I am trying to use the Darcy Weisbach equation for pressure loss. http://www.engineeringtoolbox.com/darcy-weisbach-equation-d_646.html" In Excel I have =(C4*(C5/C6))*((C7+(SQRT(C8)))/2)...

I am working on a project at my summer internship rerouting some duct work and want to do some calculations to see how much changing some of the 90 degree angles in the duct will improve flow. I don't have my Fluids text with me and was wondering if anyone knew of any good references online to...

Good morning, I'm calculating the pressure loss of a ventilation system for pot-off gas of an aluminum smelter using ASHRAE tables for fitting loss coefficients. The problem is that for much of the ducting, the diameters and flowrate ratios I have do not exist in the tables. (We're talking...

If the Earth's magma lost enough heat for it to solidify to a noticeable extent(permanent change, assuming irreversible), how would it affect its rotation about Earth's own axis and revolution around the Sun?

An isotropic solid has a refractive index of 10 at low frequencies. A 10 um thick platelet of this solid with perfectly polished planes shows two absorption bands in optical transmission. These bands, corrected for reflection, have a (negative) Gaussian shape. They occur at frequencies of 3x1012...

I found in a book the equation for the power loss caused by the heating effect of current in the transmission lines as below: Ploss = Iloss2R = (Pout/V)2R A friend of mine commented that the last bit "(Pout/V)2R" is unnecessary, confusing and wrong (but won't tell me why). Is my friend...

Hey I have a assignment to produce a excel work book to calculate acceleration time and top speeds for different gear ratios in race cars. I have so far work out time to accelerate to top speed, but I want to add a bit more detail to my graphs by showing the speed loss during gear changes...

Hi Guys, I have a problem about the loss coefficient. Head loss = K * (v^2/2g) Where K is the loss coefficients. This equation is base on Darcy-Weisbach equation. I wonder how is K varies for same flow rate, same device with a different viscosity and density. Thanks a lots in...

Homework Statement In an RC discharge circuit, R= 2.5 X10^4 ohms and C=40 microfarad. The initial potential difference across C is 25 V. Find the rate at which energy is being lost by C at 0.5 seconds. Homework Equations The Attempt at a Solution Like in this case, I probably have...

Homework Statement I'm not sure if this problem should go here.. it's a bit of math and a bit of physics. I know that the concepts should be simple but I don't really know where to start.. Here's the question: a) Determine the breakeven point for heating oil in dollars per gallon – the point...

This might be a tired topic but please help me to understand. Assume a photon moving in vacuum, ignore potential interstellar medium absorption and re-emission since it is not relevant to discussion of space expansion in this context. Redshifted photons will undergo energy loss between *right...

Hello - just discovered this forum, which has been a big help since I graduated ME 15 years ago, but never had an opportunity to practice "real" engineering...until now. I am trying to develop a spreadsheet that models friction loss, using the derivation of Bernoulli's equation, over a nozzle...

Homework Statement http://i43.tinypic.com/i1bq1i.jpg I need help with number 9 Homework Equations Wnet=change in KE Wnc=Change in Energy The Attempt at a Solution I haven't been able to get the answer marked by the computer. I tried Fs(h*cos15)=.5mv^2-mgh and that is way off...

This is probably a dumb question, but I only need to know for a program I would like to write. Basically, on average (I realize there are a lot of factors involved, but a rough estimate is all I need), how much energy dissipates over a specific length of a conductor (power lines, whatever...

Homework Statement I have to design a pumping system. Its for a swimming pool. The pool has various fittings (valves, etc) and pipe lengths. My problem is I cannot find an appropriate K value for the filter and sieve. On the suction side of the pump is various valves and a sieve to...

Hi All, I know that when water pass through a 90 degree bend pipe, there will be a pressure lose. However, how to calculate the energy/potential loss for electrical current pass through a 90 degree bend wire/resistor. Academic paper appreciated! THanks

Homework Statement For the LEP, we are given that it is a perfectly circular accelerator with circumference 25 km and that the energy of each beam is 50 GeV. Calculate the energy lost in GeV/s by a single electron on each turn. Homework Equations The loss is given by...

Homework Statement Assume no friction. A 58-kg teenager at a water park slides down a long, winding waterslide of varying slope. The slide has a net height difference of 30. m from start to finish, and the teenager starts from rest. Throughout the problem, let y=0 and Ugrav = 0 at the end...

How transformer loss vary with load current?

I've been attempting to spec a toroidal inductor--what core size, what material and how many turns? I happen to be looking at some made of the material Kool Mu. The material if ferrite, so I presume most of the core loss is hysteretic BH loss, as ferrite doesn't conduct well. Anyway, all...

Hello, I'm engineering a heat-pump for my senior project. My professor is out of town and these questions have been on my mind. I'm trying to calculate ACTUAL heat loss through the tent walls and ceiling. I'm using a tent 10ft x 5ft x 6ft. I'm trying to heat it with approx. 750 btus/hr...

Feet first... How do I calculate heat loss by evaporation from the surface of a swimming pool, at a range of temperatures and given a range of conditions? Any help gratefully received! Nick

Homework Statement What is the dB loss for a 3GHZ EM wave traveling through 2 meters of a medium with ϵ=1.5ϵ_0 and loss tangent = 9E-4? Homework Equations Umm...I'm actually not sure. I can't find anything really relating these things at all. The Attempt at a Solution My first...

Hello everyone, Quick question. When there is a pipe and you constrict it there is higher pressure loss. Is this pressure lost permanent? What is this pressure loss, is it loss as heat, are liquid molecules converted to heat, are they lost? What happens to liquid molecules if the hydrostatic...

Homework Statement A man of 75 kg (1.77 m^2 surface area) in weight, dressed in appropriate winter clothing stands on a winter pond. The temperature outside is -5 degrees Celsius. Assume that the surface layer of his skin is 5 mm thicker and is not perfused with blood (behaves as an insulating...

How can I tell the difference between a free electron that's absorbed one photon at E = hf and a free electron that's absorbed two photons at E = .5hf? If a photon at frequency f represents a '0' and a photon at frequency .5f represents a '1', then I could send out '11', have an electron...

I’m an entrepreneur in South Africa with the rights to a type of insulating coating. It’s new on the market here and no real research and development has been done on the coating to determine how much energy it can save. I’m a marketer and I don’t have the educational background to answer this...

How can I calculate energy loss from a leak in a large furnace? I currently am working on a large furnace about 1200 square feet. To heat the furnace we use a combination of air and methane at a ratio of 9.54:1. There is currently a hole in the furnace and I would like a formula to calculate...

Homework Statement A 10/1 stepdown tranformer has a full load secondary current of 50A and is rated 30kVA. The copper loss at full load is 280W. The primary winding has a resistance of 0.25ohms. The core losses are 120W. Find the resiatance of the secondary coil and the power loss in the...

Homework Statement If the specific heat capacity of water from an experiment is smaller than its actual value, does it mean more heat is lost to the surroundings? If the heat is emitted by a wire into a cup of water and the change in temperature is measured, does it mean that the change in...

Hi could someone tell me if it is possible to calculate the shear loss from a metal piston ring against the cylinder in a hydraulic pump when the outlet pressure and speed (in rpm) of shaft are known. Cheers (Updated: maybe along the lines of in cylinder pressure x piston speed x friction...

Homework Statement We are heating up the cabin log with a furnace that has strength of 4 kW. The surface of the walls of the log cabin is 35 m². What is the temperature in the log cabin, if the outside temperature is -20 °C? The thermal conductivity of wood is 0.4 W/mK; the average wall...

Homework Statement Find the mass of liquid lead at fussion temperature needed to heat up 1kg of liquid water from 20ºC to 60ºC, considering P = 1 atm, and a loss of 100 mg of water due to local vaporization. My question is: what do I do with that loss of mass? Do I calculate Q for m =...

Hi all, Is there a definite relation between un-balanced loading of a 3 phase transformer and increase in transformer loss? If so, how? Does un-balanced loading affect variable (copper) loss or fixed (core) loss? Pls. explain in detail. If I carry out load balancing between the o/p phases...

I have a large circular tank made of concrete that has a volume of 9,300,000 litres. The diameter of the tank is 48.7 meters. The side wall of the tank has a height of 4.57 meters. The tank is set into the ground by 3.57 meters and 1 meter of the tank protrudes from the ground. The tanks'...

Homework Statement If 10 kilogram of ice at zero degrees celsius is added to 20 kilogram of steam at 100 degrees celsius, what is the temperature of the resulting mixture?Homework Equations uhm... perhaps how many solutions are required to arrive at the answer?The Attempt at a Solution I and...

Dear guys I need assistance regarding optimization problem. I have to minimize the power loss in worm gear drive system. I have formulated minimization function,and constraints,how to solve the function and find design vectors. ANy suggestions,sites,ref.welcome Thank u Prakash

A system emitting gravitational radiation loses mass. But how is this explained in terms of the system. Take for example a neutron star with non-radial oscillations - this will emit gravitational waves, and lose mass. So does the number of particles in the star decrease? Or does the binding...

I have air flowing through a gate valve with lengths of pipe of matching diameter upstream and downstream. At a certain distance from the valve upstream and downstream, I am measuring static temperatures and static and stagnation pressures. I can estimate the Mach numbers at the tapping points...

I have to find the kenetic energy lost in the problem. I have both initial and final kenetic energy, how do i calculate the percent loss? I tried final over initial times 100 but that is not correct.

Homework Statement PART D this is an example from my textbook, i do not understand the result however Homework Equations U = W = Q^2/(2v) = 0.5 CV^2 = 0.5 QV the charge once connected Q1 640 micro F Q2 320 micro F V1=V2 = 80V (equating the charges to total Q0...

A spring has an unstretched length of 0.650 and a weight of 0.400kg is attached and gently lowered till eqm point is reached. The spring is then stretched by a distance of 0.200m. Loss in gpe=mgh=0.200x0.650x9.81=0.785 J Gain in EPE=0.5 Fx= 0.5 x 0.400x 9.81 x 0.200=0.392 (?) Actually I...