Question

An echo is heard 5.00 s from the initial sound and the air temperature is 25.0 °c. how far away is the barrier that reflected the sound?

Answer 1

The temperature of the air is constant, 25°C, so the sound travels at its standard speed, c = 340 m/s.

The sound must travel back as well, so:


`c = (2\cdot D)/(\triangle T), \text{ where D = distance and } \triangle T \text{ is the elapsed time}`


`D = (c \cdot \triangle T)\: /\:2`


`D = (340\:m/s\:\cdot 5\:s)\:/\:2 = 1700 m / 2 = 850 m`

Hope it helps!