Loss Definition and 841 Threads

Loess (US: , UK: ; from German Löss [lœs]) is a clastic, predominantly silt-sized sediment that is formed by the accumulation of wind-blown dust. Ten percent of the Earth's land area is covered by loess or similar deposits.Loess is an aeolian (windborne) sediment being an accumulation of: twenty percent or less clay and the balance mainly equal parts sand and silt typically from 20 to 50 micrometers per particle often loosely cemented by calcium carbonate. It is usually homogeneous and highly porous and is traversed by vertical capillaries that permit the sediment to fracture and form vertical bluffs.

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  1. F

    Total energy loss due to resistance during circular motion

    Homework Statement A tube is bent into the form of a semicircle with centre O and radius r. It is fixed in a vertical plane with its diameter horizontal, as shown in the diagram. A steel ball is held at one end A, and released into the tube. Throughout its motion the ball experiences a...
  2. J

    Rotating Polarizer 90 Degrees With Only 10 Percent Loss

    Homework Statement Describe how to rotate the plane of polarization of a plane-polarized beam of light by $90^\circ$ and produce only a 10 percent loss in intensity using "perfect" polarizers. The solution says to use 24 polarizers, with each at an angle of $3.75^\circ$ with the next...
  3. nukeman

    Loss of mechanical energy due to friction - ?

    Loss of mechanical energy due to friction - ?? Homework Statement Here, ill post the problem as a picture below, so you have all the info. Homework Equations The Attempt at a Solution I am having trouble with a: Since I don't have to worry about angles, and that the...
  4. J

    Can this classical double-slit experiment duplicate loss of interference?

    Not sure whether to put this in the QM forum or the classical forum, you'll see why-- I was thinking about the http://grad.physics.sunysb.edu/~amarch/ version of the double slit experiment, in which the information about which slit the particle went through is obtained in a somewhat unusual...
  5. P

    Calculating Energy Loss with Ballistic Pendulum

    Homework Statement How was energy lost while using the ballistic pendulum? Homework Equations Initial KE= 1/2mb*Vb^2 = 0.929J Final Potential graviational = (m+M)gh= 0.198J Energy loss = 0.929J - 0.198J= 0.731J The Attempt at a Solution I think the answer is: energy lost dues to...
  6. R

    Caculating heat loss from cooling fins?

    Hello, I am currently studying transformer design, in particular cooling methods. I am tyring to calculate the cooling effect (increased heat transfer) of adding cooling fins to a transformer. Does anyone know of some general equations/methods for calculating the increased heat...
  7. J

    Calculating the Force from Power Loss at 75.0 Km/hr

    You are testing a new car in a wind-tunnel for road and wind resistance. At a speed of 75.0 Km/hr you have found that 63.0 % of the total output power of an automobile engine is used in overcoming the resistance of the road and wind against the movement of the car. If the output power of a...
  8. J

    Calculating Force Required to Overcome Resistance of Road & Wind at 75.0km/hr

    You are testing a new car in a wind-tunnel for road and wind resistance. At a speed of 75.0 Km/hr you have found that 63.0 % of the total output power of an automobile engine is used in overcoming the resistance of the road and wind against the movement of the car. If the output power of a...
  9. M

    Energy Loss in Head on Collision of Two Cars w/Same Speed and Mass

    Homework Statement Two railroad cars, each with a mass of 7,000kg and traveling at 90 km/h collide head on and come to rest. How much mechanical energy is lost in this collision? Homework Equations KE=\frac{1}{2}mv^2 The Attempt at a Solution...
  10. A

    Why should radiation lead to loss in mass @ Black holes?

    According to theory of black hole radiation, black holes are expected to emit a thermal spectrum of radiation, and thereby loss mass, owing to the E=mc2 equation. Well, everything was clear to me till I got to the last point. why should there be loss only in mass?? couldn't the mass be same and...
  11. S

    Convection/(radiation ?) heat loss problem. (Thermodynamics)

    Homework Statement A 40-cm-long, 0.6-cm-diameter electric resistance wire is used to determine the convection heat transfer coefficient in air at 25 degrees C experimentally. The surface temperature of the wire is measured to be 150 degrees C when the electric power consumption is 90 W. If...
  12. D

    Relation between temperature loss rate and U value (transmittance)

    I am monitoring a building with temperature sensors. Observing the inside and outside temperatures I see that when the average temperature difference from inside to outside is 9.4K the speed at which the inside temperature decreases is 0.16 K/hour. I would like to know if it is possible...
  13. C

    Power loss in different drive systems?

    Firstly, I am not an engineer or engineering student. I come from an art/creative background. However, in what may be arrogance, I'm convinced I can solve a problem that no one but me thinks is a problem. Further, I'm spitting in the face of a system that has been fine for everyone else for...
  14. V

    Calculating the energy loss due to sound emission on collision

    Homework Statement I am writing my Extended Essay for IB, where I look at the possibility of obtaining accurate results in open system of a school, by accounting for all energy losses that occur during the investigation. Before conducting my experiments (which included an air track with two...
  15. C

    Calculating Heat Loss via Radiation Transfer

    Hi. I want to calculate the heat which will be lost from a body at temperature 't' to the atmosphere through radiation heat transfer. I can use Stephen's Boltzmann equation, but what should i take the temperature of surroundings as? Should it be the temperature of air or space? Thanks.
  16. B

    Reason for Loss of Mas of Planet Mercury

    A little over a year ago, I came upon the idea that the eccentricity of Mercury's orbit around the sun creates a tremendously oscillatory solar gravitational force (essentially, massive "solar tides"), which ripped the tectonically dying (now tectonically dead) planet apart.* It also included an...
  17. Y

    How to calculate power loss from a transformer

    I am currently trying to figure out how much power loss there is with a small transformer we have running VERY hot. XF info: 5kVA 120/208 to 277V %Z:5% I can't recall any power equations dealing with real transformers.
  18. S

    Heat loss whilst in steady state

    Hi all, I have a system which involves a ventilated box with a heat source located inside, if the heat source inside is say 1KW and I know it eventually reaches a steady state, in an ideal world it would reach this steady state by effectively ventilating 1KW of heat through the opening and...
  19. H

    Calculating Power & Temperature Loss from Cable

    Hi guys, I am trying to calculate the power and temperature lost from a cable. So I can do some crude thermodynamic calculations on heat transfer. I am assuming in this case that the object next to the cable is touching, and I am trying to calculate how much power and temperature is...
  20. A

    Relation between dB loss and percentage loss

    I want to know generally what the relation between dB loss and percentage loss is. If I want to know what percentage of a signals strength is lost knowing what its dB loss is, how would I accomplish that. Thanks.
  21. C

    Calculating Energy and Cost Loss in Cafeteria Tea Preparation

    Homework Statement Assume the cafeteria uses the same hot plate to boil for tea. and that it takes them 30 minutes to heat enough water for one days worth of tea (200 cups, 200g each cup) Find out how much money (in cents) would be wasted per school tear (300 days) due to inefficiency, if the...
  22. S

    Having trouble with heat loss to environment problem

    Hi guys, I kept trying different searches in Google and it kept bringing me to threads on this forum, so I thought it was time to join. I'm trying to calcuate the heat transferred into the environment from an air system and am having a bit of trouble... I really don't have very much...
  23. H

    Find the loss for the power inversion that would take place in the UPS

    Hey guys, I tried to figure this out and got a rough estimate but thought I’d ask the experts. I use the Sola SDU500 UPSs in our systems. A customer wants to know how long they will last if there is a power outage. I believe the power consumption for the entire system would be ~12Wh...
  24. P

    Maximizing Efficiency: Comparing AC and DC Sources for Charging Capacitors

    A sine wave source charge a capacitor through a diode. Is it more efficiency than a DC source charging a capacitor ? base on this https://www.physicsforums.com/attachment.php?attachmentid=17653&d=1235114409
  25. C

    Heat Loss From a Closed Box - Experimental Help

    Hi everyone. I am currently carrying out an experiment whereby I have a closed tank of water submerged in a larger tank. The water in the smaller box is heated and I am interested in the heat loss from the tank. I have done a rough theoretical calculation based on U values, where by I obtain...
  26. P

    Power Loss in transmission lines: Which method is correct?

    Here is the problem: http://postimage.org/image/1jy6nol5w/ Method 1: Steps 1. Calculate V(T1)=12*10=120V, V(T2)=10*10=100V 2. Since V(3)=10V and I(3)=1A, P(T3)=10W 3. Since not otherwise stated, Assume transformers are perfect. 4. So P(T3)= P(T2) = 10W 5. known...
  27. F

    Medical Do Fat Cells Decrease with Long-Term Weight Loss?

    I've heard that losing weight does not decrease the number of fat cells your body contains. But does this number decrease if you maintain this lower weight over time? I'm thinking that over time, the fat cells die and are replaced at a lower rate.
  28. N

    Question on the switching loss of inductive load in SMPS.

    Homework Statement Hi everyone, I have a question on the SMPS. I am studying the switching loss due to the switching action using a mosfet, it was clear in the resistive load part, the amount of loss is the integration of the changing voltage and current through the switch. However...
  29. E

    Computing Copper Loss: Examples & Reduction Strategies

    Good day. just want to ask anyone about copper loss. How is it computed for example in a manufacturing plant or in a dept mall.Could anyone give an illustration/example? Also , is it true that copper loss can be reduced by using big wires?What if the wire is big enough? thank you. hope...
  30. GRB 080319B

    Medical Permanent muscle loss in zero-g

    Why is there permanent muscle loss from space travel? Is this general muscle atrophy or specific to certain muscles (i.e., which muscles don't experience permanent atrophy and why)?
  31. E

    Loss US Academic Competitiveness hype?

    loss US Academic Competitiveness... hype? In my opinion all this hype about American students underperforming Chinese, Russian, & Korean students in math is overblown. Even if it is true it's not that big of a deal and the methodology used to come to these conclusions is flawed. In America...
  32. D

    Calculate yoyo friction energy loss

    Hi everyone! Im having a project and i need to estimate the return hight of a falling yoyo The yoyo is built of two 120cm radius and 2cm long cylinders connected by another one with a radius of 2.5cm and 30cm long. It is droped from the height of 30m with a rope that's 20m long. How can i...
  33. W

    Loss of heat from the Earth's core

    We all know that Earth's core is relatively hotter than the Earth's surface. And with this temperature gradient, there must me a loss of heat from the Earth's core to the surface and then to atmosphere and outer space by convection and radiation. So, how much time it would require for the...
  34. X

    Dark matter energy loss mechanisms

    Hi, I'm new, so this may be on the wrong board, but I thought it was more particle-energy-stuff than astro. So to the point - dark matter is non interacting with EM fields, and can't emit photons. Yes? OK, given this, how could dark matter lose energy. For example, when normal matter is...
  35. O

    Calculating Eddy Current Power Loss in Solenoid System | Copper Plate Experiment

    I have an experiment in which I have two solenoids where one induces an EMF in the other. I then introduce copper plates between the two coils and measure the decrease in induced EMF in the second solenoid. How could I calculate the power loss due to eddy currents induced in one of the copper...
  36. B

    Calculating Heat Loss from a Heat Exchanger

    Heat Exchanger! I have steam flowing past two pipes which have cold water flowing in them. I want to find out how much heat is lost from the cold water and thus the final temperature of the cold water when it leaves the pipe. I am doing this as an experiment and before I start I want to know...
  37. J

    Loss of signal power in radio and wire transmission

    Homework Statement For radio transmission in free space, signal power is reduced in proportion to the square of the distance from the source, whereas in wire transmission, the attenuation is a fixed number of dB per kilometer. The Attempt at a Solution this is not the whole problem...
  38. O

    Calculating Heat Loss from Room with Refrigerator and Heater

    A room contains 25 kg of air at 100KPa and 10 degree C. The room has a 250-W refrigerator (the refrigerator consumes 250 W of electricity when running) and 1-KW electric resistance heater. During a cold winter day, it is observed that both the refrigerator and the resistance heater are running...
  39. D

    What is the relationship between heat loss and resistivity in a cable?

    Homework Statement http://img710.imageshack.us/i/2631001.jpg/ #29 Homework Equations p=I^2R P=IV The Attempt at a Solution well, the answer is D, but i don't see why the length matters? can anyone find out the equation for this problem? i thought it was B) cable B because it has...
  40. O

    How to calculate power loss due to eddy currents

    Homework Statement What equation do i use to calculate the power loss due to eddy currents? I can't find an equation anywhere online.
  41. M

    Does Kinetic Energy Loss Equation Hold When Both Objects Are Moving?

    http://hyperphysics.phy-astr.gsu.edu/hbase/inecol.html When a block in motion(M1) collides with a a stationary object (M2) in a perfectly inelastic collision, the fraction of KE final/KE initial can be modeled as M2/M1+M2. My question is if M2 has to be stationary for this equation to...
  42. O

    How to calculate power loss due to eddy current formation?

    Homework Statement I am investigating the penetration depth of eddy currents within a copper slab. A solenoid is being used to induce the eddy currents within the copper. As a result of the experimental design, I need to calculate the power loss due to the eddy currents and I can't find any...
  43. W

    Information loss as a grid is coarsened

    Hi, Not sure if this is the correct sub-forum or not. Perhaps, general math is better. Anyways.. In the following, a simple reference covering what I am after would be very helpful. Let's say you have a 4x4 grid of cells each cell contains either a 1 or 0. Let's say it is this...
  44. M

    Calculating Heat Loss in a Home Heating System

    Hi every body This question came to my mind when I was looking at a Home Heating System. The system is a closed loop. In this closed loop of pipe hot water is flowing. I know the temperature of the pipe in the beginning and at the end of the pipe. I also know the flow rate of water in the...
  45. R

    Temperature loss - is it correct?

    Hi, is physically correct to say "loss of temperature"? Doesn't the "loss" relate just to "heat"?
  46. marcus

    Causes of loss of interest in String program

    Tom's thread "Why I'm REALLY disappointed..." continues to get increasingly thought-provoking and informative. I summarized some recent discussion here: https://www.physicsforums.com/showthread.php?p=3219363#post3219363 I had some reaction to recent posts by Suprised and Tom that I will put in...
  47. P

    What Causes High Heat Loss in Space?

    in the movie i was watching that is set in space, some of the characters get frozen while exposed to the vacuum of space without being properly insulated. Now i am wondering is my understanding of heat energy incorrect. I thought heat would be taken from the body by every atom that interacts...
  48. L

    Unexplained voltage loss in a simple voltage divider

    hey guys, I am currently trying to implement a voltage divider to step down from 9V DC for a digital output. I am using two resistors, 3.3M ohm & 2.7M ohm in series. When I measure the voltage across both of them using a multimeter I get 9.5V Across the 3.3M ohm resistor I get 2.2V...
  49. N

    Core loss when there are two simultaneous fields

    Dear all, Hi I am involved in a project and I want to model an induction machine with two three phase stators. The frequency and number of poles of the two set are different. How can I write a formula for the core loss of the stator? There are two sinusoidal waveforms at stator. Can I use...
  50. I

    Mathematics: The Loss of Certainty

    Hi I am currently reading the book "Mathematics: The Loss of Certainty" by Morris Kline ,who is Professor Emeritus at the Courant Institute of Mathematical Sciences, New York University. I downloaded the book from some free site. Here is product description from amazon.com Basically...
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