A mass weighing 13 lb stretches a spring 4.5 in. The mass is also attached to a damper with coefficient Y. Determine the value of Y for which the system is critically damped. Assume that g = 32 ft/s^2.

Respuesta :

Answer:55.227

Step-by-step explanation:

Given data

mass [tex]\left ( m\right )[/tex]=13lb

spring stretches by [tex]\left ( x\right )[/tex]=4.5in=0.375 ft

g=[tex]32ft/s^2[/tex]

Now Spring constant K

mg=kx

k=[tex]\frac{13\times 32}{y}=58.667lb/ft[/tex]

For critical damping [tex]\zeta =1[/tex]

[tex]2\times \zeta \times \omega_n =\frac{c}{m}[/tex]

and [tex]\omega_n=\sqrt {\frac{k}{m}}[/tex]

[tex]\omega _n=2.1241rad/s[/tex]

substituting values

[tex]2\times 1 \times 2.124 =\frac{c}{m}[/tex]

c=55.227 lb.sec/ft