Echoes from two parallel cliffs: distance between the cliffs or speed of sound
This type of question, asked 2 times: 18 Apr 2026 S2, 19 May 2026 S2. All 2 questions below, oldest first.
Try each one first, then open its answer.
Question 1
18 Apr 2026 S2
124A person standing between two parallel cliffs fires a gun and hears two echoes, first echo after 1 second and second echo after 3 second. The distance between the two cliffs is (The velocity of sound m/s)Tap an option to check your answer.
Question 2
19 May 2026 S2
124A man standing between two parallel cliffs fires a gun. He hear two echos one after second and the other after second. The separation between the two cliffs is m, the speed of sound isTap an option to check your answer.