contestada

A speaker fixed to a moving platform moves toward a wall, emitting a steady sound with a frequency of 230Hz. A person on the platform right next to the speaker detects the sound waves reflected off the wall and those emitted by the speaker.

How fast should the platform move (in m/s) ,v_p, for the person to detect a beat frequency of 1.00Hz? Take the speed of sound to be 344m/s.

Respuesta :

Answer:

[tex]v_s = 0.746\ m/s[/tex]

Explanation:

given,

frequency emitted by the speaker(f) = 230 Hz

beat frequency = 1 Hz

speed of the sound (v)= 344 m/s

velocity of the platform = ?

frequency heard by the observer

 f_d = 230 Hz + 1 Hz

 f_d = 231 Hz

using ,

[tex]f_d = \dfrac{f(v + v_s)}{v-v_s}[/tex]

[tex]231 = \dfrac{230(344 + v_s)}{344-v_s}[/tex]

[tex]231 (344- v_s) = 230(344 + v_s)[/tex]

[tex](231 -230)344= 230 v_s + 231 v_s[/tex]

[tex]344= 461 v_s[/tex]

[tex]v_s = 0.746\ m/s[/tex]

Otras preguntas