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Wednesday, 01 April 2026
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A boy standing some distance from the foot of a tall cliff claps his hands and hears an ...

A boy standing some distance from the foot of a tall cliff claps his hands and hears an echo 0.5s later. If the speed of sound is 340ms\(^{-1}\), how far is he from the cliff?
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  • A 680m
  • B 170m
  • C 34m
  • D 85m
Correct Answer: Option D
Explanation:
V = \(\frac{2d}{t}\)
v = 340ms\(^{-1}\)
t = 0.5s
d= ?
d = \(\frac{2d}{2} = \frac{340 \times 0.5}{2}\) = 85m

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