Question

A sound is produced at one extremity of a metallic pipe of 1000 m of length. A person being at

the other extremity discerns two sounds. (Vood in the air is 340m/s) The interval time between the two perceptions is equal to 2.5 s. Calculate the speed of
sound in the metal.

Answer 1

The sound was repeated because of the phenomenon of echo. The speed of sound in the metal is 800 m/s.

Echo results from the reflection of sound waves. The reason why a sound may be heard twice owes to the phenomenon of reflection which leads to echo.

To determine the speed of sound in the metal;

Length of metal = 1000 m

Time taken between the two sounds = 2.5 s

Using the formula;

V = 2d/t

V = 2(1000)/2.5

V = 800 m/s