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 9.00 ms.

Required:
What is the speed of sound in this metal?

Answer 1

896.5 m/s

Step-by-step explanation:

Given that :

Length of metal bar, λ= 5 m

Velocity in air, v = 343 m/s

Change in air frequency : = λ / v

f = 5 / 343 = 0.0145772 s = 14.5772 ms

Seperation time = 9ms

Change in time, t = 14.5772 - 9 = 5.5772 ms

Recall :

Velocity = Distance / time

V = 5m / 5.5772 * 10^-3 s

V = 896.50720 m/s

Velocity = 896.5 m/s