Question

The diagram shows the variation of air pressure from an alarm siren at particular instant. the speed of sound in the air is 340 m/s.

Answer 1

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Answer:

From the diagram,

(5/4)* Wave length = 1 meter

Wave length(λ) = (4/5) m------- (1)

Then we can calculate frequency(f) of alarm siren by using below equation,

V = fλ----- (2)

Where, V = velocity of the sound wave = 340 m/s

            f = frequency

            λ = wave length = 4/5 m

By using equation (1) & (2),

$340 = f * (4/5)$

$f = 340* (5/4)$

$f = 425 Hz$

But period(T) = 1/f  

         $T = (1/425)  s$

        $T = 2.35 *10^{-3} s$

      $T = 2.35 ms$

Period of alarm siren = 2.35 ms

Answer 2

Answer:

answer is 2.35 ms as the solved above