2023 · Q26
A person burned a firecracker in front of a cliff and heard its echo 5 s after it burst. The distance of the cliff from the person, if the speed of the sound is 340 m/s, is close to
General KnowledgePhysics
- A1700 m
- B170 m
- C85 m
- D850 m
Explanation
The echo travels to the cliff and back, so the time for the one-way journey is 5/2 = 2.5 s. Distance = speed x time = 340 m/s x 2.5 s = 850 m. This is close to option D (850 m); the other options either ignore the return trip (1700 m) or misplace the decimal.