Physicsmedium · Past Paper
The speed of sound in air is 340 m/s. A person shouts in front of a wall and hears an echo after 0.5 seconds. How far is the wall?
A170 m
B85 m
C340 m
D42.5 m
✓ Correct Answer: B — 85 m
d = (v * t) / 2 = (340 * 0.5) / 2 = 170 / 2 = 85 meters.
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