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~christina~
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[SOLVED] driving force- could someone tell me if I'm using the right method for probl
a 5.00kg mass attached to a spring of constant 150N/m. A driving force
[tex]F(t)= (120N)cos(\omega_d t) [/tex] is applied to the mass and the damping coefficient (b) is 6.00 N.s/m
a) what is the resonance frequency of this system?
b) what is the amplitude at resonance?
First, I'm not sure what the dt is for in the equation..
a) what is the resonance frequency of the system?
[tex]F(t)= (120N)cos(\omega_d t) [/tex]
well...I'm not sure about the F(t) since they give it in cos but I assume that I can just write it with cos and it would be the same but not sure about that.. [and what is that d in the equation?]
if I'm right then it would be:
[tex]F(t)= (120N)sin(\omega_d t) [/tex] and
[tex]F_o= 12.0N [/tex]
resonance frequency is simply this I think:
[tex]\omega_o= \sqrt{\frac{k} {m} }[/tex]
and k is given as 150N/m
and the m is 0.500kg right?
b) amplitude at resonance
not sure about this..when something is at resonance what happens?
and what equation would I use to find this?
I thought that I would use this equation but
[tex]A= \frac{F_o/m} {\sqrt{(\omega^2-\omega_o^2)^2 + (\frac{b\omega} {m})^2}}[/tex]
would Fo be the result of pluging in 0 for the time in the driving force equation given?
and is [tex]\omega[/tex] found from this equation=> [tex]\omega= \sqrt{\omega_o^2-(\frac{b} {2m})^2} [/tex]
and then used to plug into the Amplitude of driven oscillator equation to find b?
like the title of the post says, I would really appreciate it if someone could tell
me if I'm doing the problem correctly.
Thank you
Homework Statement
a 5.00kg mass attached to a spring of constant 150N/m. A driving force
[tex]F(t)= (120N)cos(\omega_d t) [/tex] is applied to the mass and the damping coefficient (b) is 6.00 N.s/m
a) what is the resonance frequency of this system?
b) what is the amplitude at resonance?
The Attempt at a Solution
First, I'm not sure what the dt is for in the equation..
a) what is the resonance frequency of the system?
[tex]F(t)= (120N)cos(\omega_d t) [/tex]
well...I'm not sure about the F(t) since they give it in cos but I assume that I can just write it with cos and it would be the same but not sure about that.. [and what is that d in the equation?]
if I'm right then it would be:
[tex]F(t)= (120N)sin(\omega_d t) [/tex] and
[tex]F_o= 12.0N [/tex]
resonance frequency is simply this I think:
[tex]\omega_o= \sqrt{\frac{k} {m} }[/tex]
and k is given as 150N/m
and the m is 0.500kg right?
b) amplitude at resonance
not sure about this..when something is at resonance what happens?
and what equation would I use to find this?
I thought that I would use this equation but
[tex]A= \frac{F_o/m} {\sqrt{(\omega^2-\omega_o^2)^2 + (\frac{b\omega} {m})^2}}[/tex]
would Fo be the result of pluging in 0 for the time in the driving force equation given?
and is [tex]\omega[/tex] found from this equation=> [tex]\omega= \sqrt{\omega_o^2-(\frac{b} {2m})^2} [/tex]
and then used to plug into the Amplitude of driven oscillator equation to find b?
like the title of the post says, I would really appreciate it if someone could tell
me if I'm doing the problem correctly.
Thank you