A 3.49 rad/s (33 1/3 rpm) record has a 4.00 kHz tone cut in the groove. If the groove is located d = 0.080 m from the center of the record (see drawing), what is the wavelength in the groove?

Respuesta :

Answer:

[tex] v = \lambda f[/tex]   (1)

And we have this other relationship between the linear speed and the angular speed:

[tex] v = rw[/tex]  (2)

We can find the linear velocity like this:

[tex] v = 0.08 m * 3.49 \frac{rad}{s}= 0.279 m/s[/tex]

And then from equation (1) we can solve for the frequency and we got:

[tex] \lambda = \frac{v}{f}[/tex]

And replacing we got:

[tex]\lambda = \frac{0.279 m/s}{4000 Hz}= 6.98x10^{-5} m[/tex]

And that represent the wavelength in th groove for this case.

Explanation:

For this case we have the following data given:

[tex] w = 3.49 rad/s[/tex] represent the angular velocity

[tex] f = 4 kHz *\frac{1000 Hz}{1 kHz}= 4000 Hz[/tex] represent the frequency

[tex] r = 0.08 m[/tex] we assume that this respresent the distance from the center

We know the following relationship between the wavelength [tex]\lambda[/tex] and the velocity of a wave:

[tex] v = \lambda f[/tex]   (1)

And we have this other relationship between the linear speed and the angular speed:

[tex] v = rw[/tex]  (2)

We can find the linear velocity like this:

[tex] v = 0.08 m * 3.49 \frac{rad}{s}= 0.279 m/s[/tex]

And then from equation (1) we can solve for the frequency and we got:

[tex] \lambda = \frac{v}{f}[/tex]

And replacing we got:

[tex]\lambda = \frac{0.279 m/s}{4000 Hz}= 6.98x10^{-5} m[/tex]

And that represent the wavelength in th groove for this case.