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Question
A person standing in front of a cliff fires a gun and hears its echo after 3s. If the speed of sound in air is 336 ms-1
- Calculate the distance of the person from the cliff.
- After moving a certain distance from the cliff, he fires the gun again, and this time the echo is heard 1.5 s later than the first. Calculate the distance that the person moved.
Solution
- `d = (s xx t)/2`
∴ `d = (336 xx 3)/2`
d = 168 × 3
d = 504 m - `d = (s xx t)/2`
∴ `d = (336 xx 1.5)/2`
d = 168 × 1.5
d = 252 m away
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