How fast, in meters per second, does an observer need to approach a stationary sound source in order to observe a 1.6 % increase in the emitted frequency?

Respuesta :

Answer:

The value is  [tex]v_o = 5.488 \ m/s[/tex]

Explanation:

From the question we are told that

     The emitted frequency increased by [tex]\Delta f = 1.6 \% = 0.016 \[/tex]

Let assume that the initial value of the emitted frequency is

      [tex]f = 100\% = 1[/tex]

Hence new frequency will be  [tex]f_n = 1 + 0.016 = 1.016[/tex]

Generally from Doppler shift equation we have that

         [tex]f_1 = [\frac{ v \pm v_o}{v \pm + v_s } ] f[/tex]

Here v  is the speed of sound with value  [tex]v = 343 \ m/s[/tex]

         [tex]v_s[/tex] is the velocity of the sound source which is [tex]v_s = 0 \ m/s[/tex] because it started from rest

         [tex]v_o[/tex]  is the observer velocity So

Generally given that the observer id moving towards the source, the Doppler frequency becomes

                   [tex]f_1 = [\frac{ v + v_o}{v + 0 } ] f[/tex]

=>                [tex]1.016 = [\frac{ 343 + v_o}{343 } ] * 1[/tex]  

=>                [tex]v_o = 5.488 \ m/s[/tex]