Okie, doing homework for physics and I'm stuck. The section is on damped oscillations, question is as follows:(adsbygoogle = window.adsbygoogle || []).push({});

A 10.6 kg object oscillates at end of a vertical spring that has a spring constant of 2.05 * 10^4 N/m. The effect of air resistance is represented by the damping coefficient b=3.00 N*m/s.

a) Calculate the frequency of the damped oscillation.

b) By what percentage does the amplitude of the oscillation decrease in each cycle?

c) Find the time interval that elapses while the energy of the system drops to 5.00% of its initial value.

Now the section in the textbook on this is extremely sparse, there are no examples and basically only one equation. Fortunately the answer is in the back of the book so I can at least tell that I am doing it wrong, but I cannot figure out how to do it correctly.

The equation I believe to be relevant to (a) is

the angular frequency of oscillation is w = sqrt((k/m) - (b/2*m)^2)

and it also says it is convenient to express the angular frequency of a damped oscillator in the form w = sqrt(W0^2) - (b/2m)^2)

where W0 is omega not and W0 = sqrt(k/m)

It seems to me these are both the same equation, but the book distinguishes between the two, and between the two frequences (one as omega not, one as simply omega), and I doubt you would need the answer to find the answer, however I get the same answer regardless. Everything I've tried for a has given me 43.97, while the answer in the back of the book is 7.00 hz.

Any help appreciated. Thx.

-Klion

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# Homework Help: Damped oscilating spring

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