Question

prove that the distance of reflecting surface should be 17 m from the source at least to hear distinct echo in air
I will mark brainlist and follow

Answer 1

speed = distance travveled/time
speed of sound is 344 m per sec
distance=?
time =1/10
344=distance/0.1
distance = 344×0.1
=34.4
is is distance of going and coming
so 34.4/2=17.2

Answer 2

Distance =speed × time

=344m/s × 0.1 s

=34.4

To hear the echo the reflecting surface is minimum half of distance I.e. 17.2m