How Do You Calculate the Damping Coefficient in a Spring-Oscillation System?

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Homework Statement


A hard-boiled egg moves on the end of a spring with force constant k. It is released with an amplitude 0.300 m. A damping force [tex]F_x = -bv[/tex] acts on the egg. After it oscillates for 5.00 s, the amplitude of the motion has decreased to 0.100 m.
[itex]m = 50.0g[/itex] (0.05kg)
[itex]k = 25.0N/m[/itex]

Calculate the magnitude of the dampening coefficient b.

Homework Equations


[tex]F = ma[/tex]

[tex]F = -kx[/tex]

[tex]v = \frac{dx}{dt}[/tex]

[tex]a = \frac{dv}{dt}[/tex]

[tex]F_x = -bv[/tex]

There is another that I can't remember for sure... IF I'm right, it goes like this:
[tex]y_0 = A_0 e^{-t/\tau}[/tex]

The Attempt at a Solution


First, I don't know how the egg "moves". Is it hanging vertically, in which I can take [itex]a = g = 9.81m/s[/itex]? Or what other orientation is it in?

Secondly, while I'm fairly sure I need to use [itex]y_0 = A_0 e^{-t/\tau}[/itex], like I did in my Physics Lab, I'm not too sure how the variable b comes into all of this. I was taught that [itex]\tau[/itex] helped control the dampening of an oscillation, and was measured in seconds, or something similar.

This is as far as I've gotten. Not sure where to turn next.
 
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