A bike racing team is picking an accelerometer to measure the vertical acceleration of a front suspension. They know that the full-scale suspension travel is ±25 mm and the maximum frequency of motion is 20 Hz. Assuming that this acceleration can be modeled as a sinusoid, what is the maximum acceleration amplitude that they can expect to measure? Give your answer in g’s.

Respuesta :

Answer:

The maximum acceleration amplitude is 40.28 g.s.

Explanation:

Given that,

Full scale suspension = 25 mm

Frequency = 20 Hz

We need to calculate the maximum frequency

Using formula of maximum frequency

[tex]f=\dfrac{\omega}{2\pi}[/tex]

[tex]\omega=f\times2\pi[/tex]

Put the value into the formula

[tex]\omega=20\times2\pi[/tex]

[tex]\omega=40\pi\ rad/s[/tex]

We need to calculate the maximum acceleration amplitude

Using restoring force

[tex]F= -kx[/tex]

[tex]ma=-kx[/tex]

[tex]a=\dfrac{-kx}{m}[/tex]

[tex]a=-\omega^2 x[/tex]

[tex]|a|=\omega^2 x[/tex]

Using equation of S.H.M

[tex]x=A\sin\omega t[/tex]

On differentiating

[tex]\dfrac{dx}{dt}=A\omega\cos\omega t[/tex]

On differentiating again

[tex]\dfrac{d^2x}{dt^2}=-\omega^2A\sin\omega t[/tex]

[tex]a=-\omega^2A\sin\omega t[/tex]

Maximum acceleration =ω²A

Which is at the maximum amplitude

[tex]a =\omega^2 A[/tex]

[tex]a=(40\pi)^2\times25\times10^{-3}[/tex]

[tex]a=394.78\ m/s^2[/tex]

[tex]a=\dfrac{394.78}{g}[/tex]

[tex]a=40.28\ g.s[/tex]

Hence, The maximum acceleration amplitude is 40.28 g.s.