Loss Definition and 793 Threads

Homework Statement If a 15kg object is released from a height of 11.58m and the objects loss in energy is 302 J, determine its velocity as it enters the container (object is being dropped straight down into a container) Assume g = 9.8m/s^2 m(object) = 15kg = w(object) = 147N s = 11.58m ΔE =...

Homework Statement I am working on a simulated lab in which we have a single particle projectile launched at a target particle (located at the center of the circular chamber) of similar weight. Once the collision takes place, I record the time it takes for the scattered projectile to travel...

i receive 220v single phase supply at my home. i have 60w incandescent bulbs installed in 2 different rooms which keep blowing almost every week (just after turning on)...There is no loss of appliances since mcb at mains resets but i have to replace bulbs every time. Is there a solution ...

Homework Statement A particle of mass m_{1} and speed v_{1} collides with a second particle of mass m_{2} at rest. If the collision is perfectly inelastic what fraction of the kinetic energy is lost in the collision? Comment on your answer for the casses that m1 is much much smaller than m2...

I have a cylindrical pipe of internal diameter of around 5mm, say capped at one end with pressurised fluid flowing though the other opening. If I have holes at the wall of the pipe, am i able to calculate the pressure loss due to water squirting out through those side holes?

Hi everyone. i have done a CFD smulation in fluent for a turbulent pipe flow and have plotted static pressure against distance x. from the graph i get a straight negtive gradient. i have been told that you should compare the pressure loss to Blasius equation and Darcy equation. How do i compare...

Hey everyone, I could do with a hand checking my understanding of calculating the current loss in cables just to make sure I am doing it right. First up, is power loss. From my understanding of ohms law and P=VI it is possible to calculate the power loss in cables by using the formula power...

Homework Statement "Calculate the reflection loss when a beam of radiant energy passes through an empty quartz cell assuming the refractive index of quartz is 1.55"Homework Equations I/I_i = ((n2-n1) / (n2+n1))^2The Attempt at a SolutionI'm taking the refractive index through the empty cell...

I'm using the app on my iPod that's for myfitnesspal. Great app to help count calories. Also, I'm doing the Zumba exercise program to help with the weight loss/tone up. Any opinions on all of this??

Homework Statement A 200m long copper wire, with cross section area of 1.5mm2, is connected with a 10Ω resistor in a series circuit, and the supply voltage is 50V. Homework Equations Find the power loss in the copper wire, when ρ=0.0175 Ωmm2/m The Attempt at a Solution R=*L/A...

Homework Statement I need to estimate the energy loss of electrons before they reach a detector, but I am unsure how to do it. I think I am supposed to integrate the stopping power function over the total distance but I can't solve the equation... Homework Equations Stopping...

Thanks.

"Bernoulli Loss" Hi, I am reading a fluid dynamics paper about dissipation due to turbulence in the fluid causing "Bernoulli loss". What exactly is meant by this? The Bernoulli principle concerns energy conservation. So, does Bernoulli loss simply refer to a loss of energy within the fluid...

I am working on a problem where I am heating a hollow cylinder from the outside with a NiCr wire which is then insulated. The pipe is cooled by running water through the center of the hollow pipe. I would like to find the heat flux transfer rate outward. So my set up from the inside to the...

For minor losses, I read that the pressure drop is equal to the dynamic pressure * loss coefficient. However, in calculating dynamic pressure, it uses a single velocity. How do you determine this velocity when it will vary at the point of change in pipe diameter or direction? I have read...

I read this very interesting article on physorg about how planetary tilt is essential to life and various things that can diminish axial tilt over time or not give rise to one; things that would make life less probable. But I came across this quote that I couldn't help but question the accuracy...

Googling for information on the topic leads me to graphs such as this, which suggest that if Beta and advance are optimal efficiency tops out at 85% or so. Some questions: 1) Is the ~15% lost energy converted to heat, or is there some stray kinetic energy in airflow that is somehow unusable as...

I know static friction can cause an object to accelerate, but also decelerate. And i also know that static friction never cause energy loss, but I wonder when it causes an object to decelerate, its kinetic energy should decrease, so where is the mechanical energy gone? Has static friction done...

Hi all, I have calculated the expected heat loss (fabric not ventilation) of a room in a house using Q=Ʃ(UAΔT) for each building element (window, door, wall, ceiling etc) making the room. The units are Watts. How can I measure the actual observed heat loss of the room? I am currently...

I just want to confirm an error I have seen on another website about discharging of batteries. The poster suggested that the mass of a battery decreases because matter is being converted into energy according to the equation E=mc2 as the battery discharges. They said that because c is so large...

how we doing i found the following information regarding finding the pressure drop in a pipe due to 90° bends. i was wondering could this be adapted for say a bend of 60° or 45°. what would be needed to change to the below information to allow this to happen?? thanking ou in advance. this would...

Using past results and Harkness ratings, Elo observed that the distribution of individual performances resembles a normal distribution" http://www.chessbase.com/newsprint.asp?newsid=4326 What exactly is this "performance"?

Here's a question I posted about 10 years ago as a member of the forum. No one seemed to provide a satisfactory answer then so maybe someone might have some ideas on the subject: When a permanent magnet attracts an object it does work and loses energy. When the object is pulled away is the...

If I understand correctly, Hawking Radiation is created when the anti-particle of a virtual particle pair falls into a black hole while the particle of the pair escapes. The anti-particle goes on to annihilate with a particle in the black hole. Is not the annihilated particle identical to the...

Hello, I am trying to calculate the heat loss of a capsule (mini submarine), size is 6m long and 0.5m radius of the ends and a height of 3m. I found a formula for calculating heat loss but it requires an R-value which I don't have, H = A(Thot-Tcold)/R (I'm guessing this is for insulated...

Hello all, I'm not sure if any of you have ever used a device that measures RF transmission line loss and presents it as a graph of Insertion Loss (dB) vs. Frequency (GHz), but that is exactly what I'm trying to calculate. I've been looking through equations for days, and I just don't...

Homework Statement Homework Equations H=-k A \frac{\Delta T}{\Delta x} kconcrete = 1.0 W / m K (approx) The Attempt at a Solution H=\frac{-1.0 (8 * 12) (10-20)}{0.23} = 4.17 kW My problem is that the book (Essential University Physics, Wolfson) has the answer as -4.17 kW, but...

Homework Statement I am working on a energy analysis in a supermarket. There is some open top display coolers, which is using a lot of energy - I don't have the opportunity to check excatly how much energy they use, so I have to calculate it. I don't have problems in calculating it when it is...

Hi, On various websites I read that 70% of the heat loss of a pool is by evaporation, whereas up to 85% of the solar radiation can heat an uncovered pool. We use 22mm thick black color EPE panels to cover our pool. On a sunny day, is it better to cover the pool or to leave it uncovered ...

kinetic energy loss?? A 2850 kg car moving east at 8.0 m/s collides with a 3200 kg car moving east. The cars stick together and move east as a unit after the collision at a velocity of 4.86 m/s. (a) Find the velocity of the 3200 kg car before the collision. 2.06 m/s to the east (b) What...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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...

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.

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...

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.

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...

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...

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.

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...