Question

A hammer taps on the end of a 4.2-m-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 9.00 milliseconds . What is the speed of sound in this metal?

Answer 1

Metal is a solid, the velocity would be faster, so the first pulse would arrive 9 ms before the air pulse. thus,
\[\frac{ 4.2 }{ v(air) }-\frac{ 4.2 }{v(metal) }= 9 ms\]
if you know v(air) you can calculate v(metal)

Answer 2

Thank you!

Answer 3

you are welcome.