# Work and energy in simple harmonic motion concept

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1. Oct 25, 2015

### **Mariam**

1. The problem statement, all variables and given/known data
Is the statement cirrect: "the rate at which a wave transfers energy depends on the amplitude at which the particles of the medium are vibrating."

And does the energy=A^2 ?
2. Relevant equations
E (proportional) A^2

3. The attempt at a solution
For the statement I am about confused, because I think that the rate mentioned refers to velocity of the wave and that's constant (in a given medium and temperature). I also believe that the higher the amplitude the more energy the wave will carry but how will that affect rate of energy transferred?

For the second question, I think that the equation should be E=(1/2)k*A^2

(Where A is max displacement or amplitude)

Thanks :)

2. Oct 25, 2015

### ogg

dA/dt = kA....right? this answers the first question. The second question is lots more ambiguous. When EVER you have an equation of the form A = bC, you can ALWAYS pick UNITS such that A' = C'. (These units are almost NEVER standard SI (or any other official) units). So, the second answer is "maybe" ...my answer would be "no, not unless you choose units in which k was 1 (unitless)"...but that's an advanced position for a beginning student to take.