## damping coefficient

A 50.0-g hard-boiled egg moves on the end of a spring with force constant . It is released with an amplitude 0.300 m. A damping force acts on the egg. After it oscillates for 5.00 s, the amplitude of the motion has decreased to 0.100 m.Calculate the magnitude of the damping coefficient . Express the magnitude of the damping coefficient numerically in kilograms per second, to three significant figures

pls who can help me?
thanx

 PhysOrg.com science news on PhysOrg.com >> Front-row seats to climate change>> Attacking MRSA with metals from antibacterial clays>> New formula invented for microscope viewing, substitutes for federally controlled drug
 Recognitions: Gold Member Homework Help Science Advisor How should Newton's 2.law of motion look like?
 i think it is: -kx-bv=ma

Recognitions:
Gold Member
Homework Help

## damping coefficient

That's correct!
Now, what type of solutions have you learnt that this differential equation has?

 Recognitions: Homework Help See it as $$-kx - b \frac{dx}{dt} = m\frac{d^2 x}{dt^2}$$
 v= dx/dt and a= d^2/dt^2
 but what is the answer of d^2/dt^2 then?
 Recognitions: Gold Member Homework Help Science Advisor mlee: Any progress at what sort of solutions your equation has?
 uh not really...;(
 Recognitions: Gold Member Homework Help Science Advisor Now, I'd like you try a solution of the form: $$x(t)=Ae^{rt}$$ (A and r constants) What condition must be placed on "r" in order for this to be a solution. Please post your work.
 Asin(wt)+Bcos (wt)

Recognitions:
Gold Member
Homework Help
 Recognitions: Gold Member Homework Help Science Advisor You lack a minus sign in your exponential! Now, knowing a) The initial displacement and b)That the initial velocity is zero How can you determine $$A,\phi$$ Besides, what is your value of "w"?