A damped mass/spring system takes 14.0 s for its amplitude of the oscillator to decrease by a factor of 9. By what factor does the energy of the mass/spring system decrease over that time?

Respuesta :

Answer:

The correct answer is "0.246".

Explanation:

Given that the amplitude is decreased by a factor of 9, then

[tex]A \rightarrow (A-\frac{A}{9} )[/tex]

[tex]A \rightarrow \frac{8A}{9}[/tex]

As we know,

Energy will be:

⇒  [tex]E_{1}=\frac{1}{2}KA^2[/tex]

and,

⇒  [tex]E_{2}=\frac{1}{2}K(\frac{8A}{9} )^2[/tex]

          [tex]=\frac{64KA^2}{162}[/tex]

⇒  [tex]\Delta E=E_1-E_2[/tex]

On putting the estimated values, we get

           [tex]=\frac{1}{2}KA^2-\frac{64KA^2}{162}[/tex]

⇒  [tex]\frac{\Delta E}{E}=\frac{\frac{20}{162}KA^2}{\frac{1}{2}KA^2}[/tex]

          [tex]=\frac{40}{162}[/tex]

          [tex]=0.246[/tex]