Question

Calculate the minimum distance of which a person
should stond en foord of a reflecting surface to be
able to hear mecho '<speed of sound in air= 350
m/s).​

Answer 1

Answer:

The human ear can hear two sounds distinctly only if there is a time interval of 1/10 seconds between them. Now, the speed of sound in air at 20 ° C is 340m/s.

so the distance traveled in 1/10 seconds will be:

Distance = Speed X time

=340×1/ 10

=34m

Thus, it is possible to hear the echo at the minimum distance of 34/2=17 m between the source of sound and reflecting surface.

hope it helps uhh