Question

ąŋʂῳɛƦ ℘Ɩʂ..

ᴡʜᴀᴛ ɪꜱ ᴛʜᴇ ᴍɪɴɪᴍᴜᴍ ᴅɪꜱᴛᴀɴᴄᴇ ɴᴇᴇᴅᴇᴅ ꜰᴏʀ ᴀɴ ᴇᴄʜᴏ?​

Answer 1

$\sf\underbrace\red{Required \: Answer :}$

16.5m

Thus, to hear the echo clearly in the air, the reflecting surface should be at a minimum distance of 16.5m from the source of sound.