Loss Definition and 793 Threads

When solving a Diff. Eq. how do we know that y=0 is another solution lost when we solved it?

Homework Statement Radio 4 transmits on FM at a frequency of 92.5 MHz Calculate the wavelength and use it to explain why listeners in deep valleys cannot pick up radio 4 FM. Homework Equations The Attempt at a Solution

All the info I could obtain talks about heat loss through windows and doors. I am trying to get several store owners in my town to close there doors in the middle of winter and summer. The average door is 28 sq ft. I am assuming the inside temperature is 68 degrees and the outside temperate...

Hi, I am doing an experiment to investigate the propagation loss in some nanophotonics structures. The laser light is coupled to the input of the DUT chip via a tapered lensed fiber and the output of the chip is go through a objective then a photodetector. The chip is design for...

how to calculate head loss due to sudden enlargement in case of compressible fluid? hiiiiii guys, am graduate student, i want to know @ head loss in case of compressible fluid due to sudden enlargement...pls help me ...as soon as possible...

Homework Statement A stack of identical coins is all at a temperature of 100 C. The coins are transferred to a container of room temperature water. After thermal equilibrium is reached the final temperature is 35 C. The Heat lost by a single coin is less/greater/equal to the heat lost by all...

Hello, I know that something around 65% of the potential energy stored in fuel is lossed in an engine through heat. I am trying to find exactly how its lossed, I know some is through piston friction, and some is lossed through the exhost, but I can't find how much is lossed for each...

[FONT="Arial Black"][SIZE="4"]Hi all, Homework Statement I'm stupefied. In continuation to my last thread (https://www.physicsforums.com/showthread.php?t=277124), I wanted to see if any perfectly plastic collision would make the total mechanical energy of the system go down to a factor of...

The power loss is given by I ^2 R where I is the current and R is the resitance. I know why these variables are in this equation. V = I R P = I V therefore, P = I² R What I don't understand is the practical explanations for this. Why are there two current variables? Are there two...

How can I calculate the heat loss from the surface area of a box into air? Also, how can I calculate the heat/energy loss from a heated gas (into ambient air)?. Thanks in advance.

Hello, How can I determine the heat loss (to air) from a box of a specific material, with a heat source inside of it? Also, how do you calculate the heat/energy loss of a heated gas into ambient air. Thanks

Homework Statement Solve the heat equation: u_{t} = u_{xx} - u - x*e^{-t} BC: u(0,t) = 0, u(1,t) = 0 IC: u(x,0) = x Homework Equations The Attempt at a Solution The only progress I've made so far is figuring out that the steady state solution is zero. Other than that I don't...

Does anyone know of an experiment or know where I can find an experiment to compare the heat gain or heat loss by a conductor and an insulator?

During 4 hours one winter afternoon, when the outside temperature was 5° C, a house heated by electricity was kept at 20° C with the expenditure of 45 kwh (kilowatt·hours) of electric energy. (a) What was the average energy leakage in joules per second (watts) through the walls of the house to...

Ohmic loss, ohm's law, resistance etc... hello, just a simple question about power dissipation in the form of heat. If a conductor has infinite conductivity (zero resistivity) then the voltage across it is zero, so by the formula P= I^2 R, it dissipates zero power as heat. but if I use...

Power station generates 120kW Electricity can be transmitted either at 240V or at 24000V using a step-up transformer. The cables have total resistance of 0.4W What is the power loss when voltage is transmitted at: 1) 240V 2) 24000V I AM SURE YOU CAN WORK THIS OUT USING I...

Hi. Imagine a closed physical system (a universe) with only one star like our Sun, and one planet like our Earth, but so far away from each other, that the gravity from both matters only has a very small effect on each other. There is a (almost maximum) gravitational potential energy...

http://extras.mnginteractive.com/live/media/site297/2008/0808/20080808_051413_wall_arch_before-after-1_300.jpg http://www.sltrib.com/news/ci_10142089?source=rss "Wall Arch, one of the most accessible major arches in the Devils Garden area of Arches National Park, collapsed sometime Monday...

Hello. I've recently been using a few different numerical integration methods to solve a number of different problems, and as I looked into the integration algorithms, I realized that I don't understand them as well as I thought I did. I created a simple Excel workbook that calculates the...

3500 calories equals about 1 pound. However, you can get 3500 calories and 500% of your daily fat intake. Does that mean you will gain more weight? As far as I can tell, you gain the same amount except you are gaining an unhealthy amount of your calories from fat (losing out on nutrients). Maybe...

Homework Statement A rectangular building is being designed to minimize heat loss. The east and west walls lose heat at a rate of 10 units/m^2 per day, the north and south walls at a rate of 8 units/m^2 per day, the floor at a rate of 1 unit/m^2 per day, and the roof at a rate of 5 units/m^2...

I'm "aware" of current theories about the cyclic model but what's wrong with this hypothesis? The universe starts crunching forming a big black hole All the energy is sucked back into this big black hole The big bang starts again with all the matter and energy as the previous big bang...

Tried to figure this out for a friend but couldn't quite get it. Here is the problem. For 3 hours one winter afternoon, outside temp is 0* C. A house is heated and kept at 20* C with the expenditure of 45 kwh. What was the average energy leakes in joules per second through the walls of the...

Alright, I'll need some help formulating this, since my writing tends to be... well... just not very eloquent and representative of my thoughts. I don't believe in soul, afterlife, or other nonsense. I think our self, our consciousness, is a function of our complex brains. For what...

How much mass does the sun lose every year?

if an object is made of particles that are interacting via electric and magnetic fields that propagate at the speed of light then does it not follow that a moving object will experience a loss of simultaneity? in other words, it is not necessary to go outside of classical physics to explain...

Hello, I'm working on a Time Of Flight simulation to detect some pair/particles and I need some information about the "Energy dependence of the light yield of PST scintillators" Does anyone have information about this? Thank you in advance.

[FONT="Georgia"][SIZE="3"]Homework Statement When a current of 2A flows the p.d across a battery's terminal falls from 12V to 9V. (a) What is the value of the loss volt? (b) What is the internal resistance of the battery? Homework Equations Lost Volt = Ir The Attempt at a Solution...

Homework Statement I am required to plan an investigation to find out how changes in the consumption of protein in the diet influences the excretion of urea in humans. Apparatus: 10g per 100cm3 (10%) solution of urea. Urease tablets or 5g per 100cm3 (5%) solution of urease...

Homework Statement In this problem you will estimate the heat lost by a typical house, assuming that the temperature inside is T_in= 20degrees C and the temperature outside is T_out = 0degrees C. The walls and uppermost ceiling of a typical house are supported by 2 x 6-inch wooden beams...

If a fluid has reached steady flow, ie constant velocity, yet there is friction created by the shear stress of the wall, i don't understand how the pressure can drop. I tried using bernoulli to see how this would happen, but i can't see it. If the velocity doesn't decrease, i don't understand...

I need to plan an investigation to find out how changes in the consumption of protein in the diet influence the excretion of urea in humans. it is possible to determine the urea concentration in urine using the enzyme urease which catalyses the following reaction: Urea+Water --> (with...

What if there is no hawking radiation i.e if it is not proved..i think it is not yet proved...so will it have any influence on information loss paradox..if there is no hawking radiation then the information would be inside black hole and not accessible..so there is no information loss paradox if...

Hi, I am an undergraduate, doing an experiment regarding of minor losses due to sudden contraction. However, I found that my theoretical loss is higher than the experimental loss. The flow rate = 3.28*10^-4 (m^3/s) (Inner diameter) D1= 3.652*10^-2 m (Inner diameter) D2= 1.539*10^-2 m by...

[SOLVED] Mass of N loss Homework Statement 1.00kg block of Cu at 20C is dropped into a large vessel of liq Nitrogen at 77.3K. How many kg of Nitrogen boil away by the time the copper reaches 77.3K? specific heat of Cu is 0.0920cal/g C. The latent heat of vaporization of Nitrogen is 48.0cal/g...

When a solid body is moving on any hard surface due to friction it will lose some very little part of its body; as when we take a broken piece of glass and rub it on the concrete surface, it loses some mass of its initial mass. so, what is the general formula of finding the lost mass due to...

Circuit 3(connected to a 3v battery,C2 and C3 in series, C1 and C23 in parallel) C2 C1 C3 c1=c2=c2=1F Circuit 4(Two unequally charged capacitors are connected to each other,from setup above) C1 C2 In circuit 4, after the...

From nuclear theory and texts its known that every second 570 millions tons of hydrogen are converted to 566 millton hellium,hence Sun loss 4 mill tons of mass in a second. But ¿how do astrophicisist probe experimentally this number?,have they measured solar gravity field or Earth atraction...

How can I measure the total energy loss of a Newton's cradle until it comes to rest. The only variables I am given are the horiztonal displacements for each swing (how far the ball travels out after it rebounds off the other balls) and the angle. I have no idea where to start, I was told I...

can someone explain information loss paradox in layman terms without using any quantum physics terms...i read in some sites but i couldn't understand as they are explaining using some jargon terms...

Strangely, this is for a Mat Sci Class. It is probably not as complicated as I am making it out to be, but the book has no suggestions on how to handle this problem. Homework Statement Calculate rate of heat loss through a fireclay refractory wall of wall with thickness .1m. Furnace...

I'm a first-year EE grad student at a prominent university, and I feel like I'm at an impasse. Basically, I've lost all interest in my research, as well as my (once strong) peripheral interests in physics and math. I have no more motivation. At the risk of sounding like I'm venting, I really...

[SOLVED] Conservation of Energy With Loss Due to Friction Homework Statement The cable of an elevator of mass m= 2690 kg snaps when the elevator is a rest at one of the floors of a skyscraper. At this point the elevator is a distance d= 75.0 m above a cushioning spring whose spring...

I have some extended aluminum part which is at low temperatures. It is connected by a thin alu rod to a cooling device held at a constant temperature. How can I estimate the rate of cooling through this thin rod given the material specific constants? I assume the heat exchange with the...

http://www.independent.co.uk/news/science/scientists-discover-way-to-reverse-loss-of-memory-775586.html

A parachutist with a mass of 50.0 kg jumps out of an airplane with an altitude of 1.00 x 10^3 m. After the parachute deploys, the parachutist lands with a velocity of 5.00 m/s. Find the energy that was lost to air resistance during th jump. I tried using this: W = Kf – Ki → W = ½ mv^2 (f) –...

Homework Statement Heated air at 1 atmosphere and 35 deg. Celsius is to be transported in a 150 meter long circular plastic duct (smooth) at a rate of 0.35 cubic meters/sec. If the head loss in the pipe is not to exceed 20 meters, determine the minimum diameter of the duct. Homework...

I'm doing research on window functions (such as: rectangular, Hanning, Blackman, etc), but am having trouble with respect to the energy loss associated with each. I know that applying the window causes energy loss in the spectra of interest, and for the Hanning Window and Hamming window...

Homework Statement a power station delivers 520kW of power to a factory through wires of total resistance of 3 ohms ,how much less power is wasted if the electricity is deliverd at 50,000V rather than 12,000V Homework Equations P=IV=I^R =V^/R The Attempt at a Solution I tried to...

new problem! A pumped-storage reservoir sits 136 m above its generating station and holds 9.0×10^9 kg of water. The power plant generates 346 MW of electric power while draining the reservoir over an 6.9 h period. What fraction of the initial potential energy is lost to nonconservative...