What is the minimum distance from a reflecting surface needed to hear a distinct echo in air (speed of sound about 340 m/s)?

Answer as guest — Start Free Practice Test to earn Practice PointsHow to earn pointsAsk a question+3Answer a question+1Someone answers yours+1Your Q gets upvoted+1Pioneer bonus (first 5)+51 point = ₹1 discount on purchases, ask questions & climb the leaderboard!

• A 8.5 m
• B 17 m
• C 34 m
• D 68 m

Submit Answer