Loss Definition and 841 Threads

Homework Statement My textbook says that high voltages are used for power transmission because according to the equation P=VI and P= I2R, power loss can be reduced. What confuses me is why the equation P=V2/R cannot used here? And if used, would be contradictory? I know that R is the...

Homework Statement A high-speed optical data communication system is composed of a transmitter, an unamplified transmission fiber link, and a receiver. The optical transmitter generates a 10-Gb/s non-return-to-zero (NRZ) signal using a 1550-nm laser diode (linewidth=2 MHz) followed by a...

Homework Statement why the formula of fricitional pipe loss due to contraction is given by formula : kc(V^2)/2g ? why the formula of fricitional pipe loss due to contraction can't be formula : (Va^2)-(Vb^2)/2g ? ,where Va= velocity at inlet , Vb = velocity at outlet ? Homework EquationsThe...

Hello, I was just wondering why is there an energy loss in helicoidal movement, specially in syncrotons. I know that there is energy loss because there is a production of X-rays, why this happens?

Hello everyone, Where can i get dielectric loss values of very thin SiO2 layers (nm) at high frequency range (GHz).? i.e SiO2 oxide layer dielectric loss of MOS (metal-oxide-semiconductor). I searched a lot on net but i didn't find any useful result, any reference is greatly appreciated.

Homework Statement what does the author mean by D2/ D1 = 0 ? when D2/ D1 = 0 , the pipe doesn't exist , right ? Homework EquationsThe Attempt at a Solution

Homework Statement i know that the formula of head loss is (V^2) / 2g , where v =velocity , but , why did the author want to change it to k[(Q)^1/n ] ? Homework EquationsThe Attempt at a Solution

Homework Statement This is a Lab: A Ball is placed on a 14cm high ramp and it rolls down to the bottom of the ramp and onto a table where it rolls 20cm (the ramp's horizontal displacement is 16.5cm). After rolling on the table, the ball falls off the table for 76.5cm with a forward horizontal...

Someone please help me understand this concept that has always confused me: Is the movement of the turbine itself a loss of efficiency since that is energy that is not being converted into other (e.g., electrical) energy? For example, if a wind turbine is not hooked up to anything, it will...

Homework Statement This is simply a sanity check concerning the system described and attached. My concerns are detailed within my attempts at the solution. Any guidance will be greatly appreciated! The diagram attached represents a process for which a pump and associated pipe work require to...

Homework Statement Consider the circuit shown below. a) What is the total power loss for the whole circuit? b) What is the power loss through R1? c) What is the power loss through R2? d) Find the voltage across each of the three resistors. I didn't do this myself. I have no idea what's going...

What about the structure of glass allows light to pass through, lose 10% of its energy then keep on going when all other object seem to absorb light. what makes clear objects structures so special. When the lights goes through the (regular) glass and loses energy is it losing energy in the form...

Homework Statement A 65-kg woman descends in an elevator that briefly acclerates at 0.20g downward when leaving a floor. She stands on a scale that reads in kg. (a) During this acceleration, what is her weight and what does the scale read? Homework Equations ƩF = maThe Attempt at a Solution I...

Homework Statement This is a simple question but I can't seem to solve it( I don't know if this is advanced physics or not first time on this website, it said Work and that is part of this energy loss problem) here is the problem: What percentage of its gravitational potential energy does a...

Homework Statement Hello everyone, I hope that you guys could lend me a hand. I need to calculate the heat loss at any point over a long pipe while considering lambda of the pipe. I am trying to use octave to find a reasonable flow-rate to keep the temperature loss to a minimum at a reasonable...

Usually it is said that loss of heat through a chunk of material because of conduction is proportional to difference in temperature and inversely proportional to thickness of material. E.g. if I got a wall to ΔQ = K*S*ΔT/D. where ΔQ - is energy flow through material. K - constant characteristic...

I'm 6 months into a PhD (admittedly in Chemical Engineering, not physics, but my project has a modelling bent) and, as the title suggests, I've been struggling to find motivation day in and day out. It's silly: give me an interesting problem in a project not related to my work (say a math...

Homework Statement what does the gamma in the formula mean ? since the other terms in the formula are the same , i can just cancel it, leaving μ / γ = v /g . So , γ has unit of kg(m^-2)(s^-2) ? Homework EquationsThe Attempt at a Solution

I have just seen a brief clip of an article by a journalist regarding a lecture given by Hawking this week about the mystery of where information of a star goes to when it is swallowed by a black hole. As a non physicist, I am grappling with what exactly is meant by this. Isn't this just a...

Homework Statement Hi! I need to find the opening angle of the loss cone at a given altitude, when the magnetic latitude is 65 deg. Homework Equations See below The Attempt at a Solution First, I used the following equation to calculate the magnetic field at a given altitude...

Hi. I use maxwell 3D eddy current solution type. i want to find out core loss. please help me.

I have a spinoff on this question: https://www.physicsforums.com/threads/static-and-dynamic-pressure-in-a-cyclindrical-pipe.768080/#post-5340726 I have a pipe where flow enters at v1 . The pipe discharges into a volume which then continues with other pipes etc to ambient. I need to put a...

Homework Statement One hundred tombola tickets were sold, numbered 1-100, at 25p each. Each ticket which included a '5' won a prize costing 50p. Each ticket ending with a '0' won a prize costing £1. If all 100 tickets were sold, how much profit was made? Homework Equations 100 tickets costing...

As a long time Debian user and as a human being, I was shocked this afternoon when I received an email https://www.debian.org/News/2016/20160105 announcing the passing of the project's founder.

Homework Statement A 400kV line is carrying 1GW of power and experiences a line resistance of 5 ohms. What is the power loss in the cable due to resistive losses? Homework EquationsThe Attempt at a Solution You are given 4 potential answers to this question a) 3.2x10^7 W b) 78 W c) 5000 W d)...

I find most textbook explanations of resonance lacking. My understanding is that resonance occurs becuase less "driving energy" is lost when the driven frequency approaches the natural frequency of a system. But why does the energy loss curve like this? Since Q-factor is different for each...

Homework Statement Hi, as a part of my lab report I have to conduct this experiment : Fill a pot with tap water and boil it, determine then how much of the energy that the kitchen surface produced, actually went to the water itself. Consider the water having an initial temperature of 10 °C. In...

Homework Statement I am wondering how the mass of a ball affects the percentage of energy loss when the ball bounces. Homework Equations Ep=mgh eff=eout/ein x 100% The Attempt at a Solution 1)I don't think it affects them because if the ball is heavier but still made of the same material it...

I am wondering how the mass of a ball affects the percentage of energy loss when the ball bounces 1)I don't think it affects them because if the ball is heavier but still made of the same material it has the same elasticity and density only mass has changed. But if all of the starting Ep goes...

A small factory has decided to go Carbon neutral and has installed its own wind turbine. The wind turbine is installed on land belonging to the factory 1 km away. The factory owner needs 2km of copper wire of diameter 3mm to connect the turbine to the factory. The resistance of the cable is 1.2...

Homework Statement We recently did an experiment in class and we were asked to get some ideas together to try and explain our results. We measured the time it took water to fall from 70 degrees to 65 degrees C. The water was placed in a shiny steel container (which had a volume of about 400ml)...

Hello folks, I'm looking for a way to measure core loss in RF transformers and inductors. I found a PhD thesis here: https://vtechworks.lib.vt.edu/bitstream/handle/10919/19296/Mu_M_D_2013.pdf which looks like just the ticket, but I'm having trouble understanding key parts. I've tried...

Homework Statement An electric fan which is plugged into a 115 V(rms), 60 Hz socket in your house can be considered as made up of a 1500 Ω resistor in series with a 1.4 H inductance. How much power is dissipated by this electric fan on the average? (in W) Homework Equations P = IV = I^2 R I =...

Homework Statement Biomass with a heating value of 15 MJ/kg burns in steam generator at a temperature of 1200K and all of the heat is given to the steam at a temperature of 600K. The ambient temperature is 300K. Calculate exergy of combustion products, steam and the loss of exergy.Homework...

Homework Statement Prove that a perfectly inelastic collision loses more kinetic energy than a partially inelastic collision. Given: $$m_1, m_2, v_{1i}, v_{2i}, v_{1f}, v_{2f}$$ Homework Equations $$KE = \frac{1}{2}mv^2$$ The Attempt at a Solution From conservation of momentum...

Hi, If I have a ball at the top of a ramp, it will have rotational and translational kinetic energy as it begins moving. If the ramp was frictionless, just to confirm, would it be possible for the ball to rotate or would it just slide with the point of contact on the ramp fixed? Also, if there...

I've been searching around the web to figure out why photons shift towards the longer wavelengths as they travel from stars and other light sources but I haven't figured out why they loose energy as they travel ( and after reading some web pages I was told that they don't even loose the energy...

I've been trying to lose weight a few times but each time failed not knowing what to eat. What should I be eating to burn as much fat as possible? I know I should avoid carbohydrates and drink water regularly. Does eating salad changes anything? What else should I be eating? Currently weighing...

If you had a fluid in a pipe, with say, 10m of head pressure, what would happen when the head losses of the pipe equaled the head pressure?

1. Homework Statement Express the beam energy loss in the accelerator in terms of the change in the beam momentum. It is taken from one paper, where \begin{equation} \Delta T = \left( \frac{1+\gamma}{\gamma}\right) \frac{T_0 \Delta p}{p_0} \end{equation}expression is used for transition from...

I've always been taught that in a piping system (only water), if the flow rate doubles, then pressure loss quadruples. But when using the Darcy-Weisbach equation I often find that it is closer to triple. Playing around with viscosity and temperature I've never been able to bring the ratio higher...

I was reading an article about how Heineken has replaced its short stubby bottles with the standard American longnecks, with reason: In 2013 the company replaced its old stubby bottles with a fashionably long-necked version that supposedly keeps the beer cold longer...

Homework Statement Hello,I've always been told at school that conductors have resistance, and that resistance causes energy loss when current is flowing through the conductor, but I've never known the explanation behind that resistance. Reading a little bit online, I saw 2 explanations: 1...

As seen in the drawing attached, there are two circles, the first circle will be a container to hold water and the outer is a second layer of aluminium, in between these will be insulator. What is the best way to work out minimum space lost by using triangles/sectors to fill this area? Having...

Suppose a block of 10kg at 10m/s collides into a block of 5kg at 0m/s. Does a given percent of energy loss in the collision affect the final velocity of the blocks after the collision? For instance, if there is no energy lost in the collision, would the final velocities be faster than if...

Homework Statement Block m1 has mass 10kg and 10m/s Block m2 has mass 5kg and 0m/s Energy loss is 0%Homework Equations Conservation of momentum Conservation of energy Quadratic Equation The Attempt at a Solution (mv)1i + (mv)2i = (mv)1f + (mv)2f 10(10) + 5(0) = 10(v)1f + 5(v)2f v_{2f} =...

Energy efficiency related question: please help with an anwer to the following: Given a flat electrical coil of known dimentions, this coil is used as an induction coil, laid flat, on top of the cooking surface of an induction cooker. Basically, the induction cooker has a copper braided coil...

Homework Statement I did an experiment in which I bounced a ball under a motion sensor. From that I got a generated graph on the computer in the shape of a parabola. The max height of the ball at each interval was also obtained from looking at the graph. From the maximum height values, I...

Homework Statement The question I have is not how to arrive at the correct values of final velocity, but once I have the values of final velocity, how do I know which velocities (which are computed from a quadratic equation) are correct? Two blocks, block A and Block B, are traveling to the...

After running MCNP5, the output run terminated because 10 particles got lost how i can fix this problem ?