Energy loss Definition and 160 Threads

When middle C on a piano (frequency = 262Hz) is struck, the vibration of the piano string loses half its energy after 4s. (i) What is the decay time for the energy? (ii) What is the Q-factor for this piano wire? (iii) What is the fractional energy loss per cycle? SHM has been going great...

I need to show Integral( u(x, t)^2 dx from a to b) <= Integral( u(x, 0)^2 dx from a to b). In other words, energy is lost with time. This is what I have so far, but I get stuck near the end. Let F(t) = Integral( u(x, t)^2 dx from a to b) F(t) - F(0) = Integral( dF/dt dt from 0 to t)...

Hi, I do not know how to drive an experession for energy loss of damped oscillator.I know that: X(t)=A exp(-Beta*t)cos(wt-delta) and: v=dx/dt... I found E=K+U but it seems to be so messy. It is like: E=(1/2)*m*(A^2)*exp(-2*beta*t)[ beta^2 (cos(wt-delta))^2)+beta* sin...

could the lost energy from light cause the expansion of space? i know we have no evidence that light can lose energy but over a long distance and i mean like a Mpc or more. TO me this almost seems like a chicken and and egg question.

There will be no waves for the transerve wave any more after a period of time, why? Disturbance is added, it starts to move. Where does the energy lose? Why do the particles always try to archieve at their equilibrium level(position)?

Q. A disk of mass M1 = 350 g and radius R1 = 10 cm rotates about its symmetry axis at finitial = 198 rpm. A second disk of mass M2 = 198 g and radius R2 = 5 cm, initially not rotating, is dropped on top of the first. Frictional forces act to bring the two disks to a common rotational speed...

Okay, so the question is an electron of energy 100 MeV collides with a photon of wavelength 3x10^(-3) m (ie: the CMB). What is the maximum energy loss of the electron? After doing a few derivations for formulae, I came up with this one at work...could someone please let me know if there is...

I am climbing 1600 flights of stairs . Total height climbed is 1000ft. I weigh 60 kgs. What is the energy loss in calories? To lose the same amount of energy how long I have to walk on a flat surface at 5 Km per hour? Thank you Reena

I have a question I hope someone can help me with. Does light ever spontaneously lose energy? What I mean is, would, say, an infrared wave be traveling along and suddenly shift to microwave radiation, and maybe later to a radio wave, without any outside influences having affected it? If...

Here I go... I think the world would be better if more of it's inhabitants do what they think is best for all of it's inhabitants overall.I think this would lead to a huge decrease of mistreatment of living beings. This could be for example the murder of animals for their meat instead we might...