Question

A hammer taps on the end of a 5.0-mm-long metal bar at room temperature. A microphone at the other end of the bar picks up two pulses of sound, one that travels through the metal and one that travels through the air. The pulses are separated in time by 8.40 msms .What is the speed of sound in this metal?

Answer 1

Answer:

810.37 m/s

Explanation:

s = Displacement = 5 m

$v_a$ = Speed of sound in air = 343 m/s

Time taken to travel the distance

$t'=\dfrac{s}{v_a}\\\Rightarrow t'=\dfrac{5}{343}\\\Rightarrow t'=0.01457\ s$

Time for the sound in metal

$t=0.01457-8.4\times 10^{-3}=0.00617\ s$

Speed of sound is given by

$v=\dfrac{s}{t}\\\Rightarrow v=\dfrac{5}{0.00617}\\\Rightarrow v=810.37277\ m/s$

The speed of sound in the metal is 810.37 m/s