Question
A man stands in between two parallel cliffs and blows a whistle. He hears first echo after $0.6s$ and second echo after $2.4s$. Calculate the distance between cliffs.
[Speed of sound $= 336 m/s]$
[Speed of sound $= 336 m/s]$
✓
Answer
Given: $t_1 =$ Time after which first echo is heard $= 0.6s$
$t_2 =$ Time after which second echo is heard $= 2.4s$
$v =$ Velocity of sound = 336 m/s.
For an echo the distance travelled by the sound is 2d.
$d _1=\frac{ v \times t _1}{2}$
Or, $d _1=\frac{336 \times 0.6}{2}=100.8 m$
And $d_2=\frac{v \times t_2}{2}$
Or, $d_2=\frac{336 \times 2.4}{2}=403.2 m$
$\therefore$ Total distance between two cliffs
$= d_1 + d_2 = (100.8 + 403.2)m = 504 m.$
$t_2 =$ Time after which second echo is heard $= 2.4s$
$v =$ Velocity of sound = 336 m/s.
For an echo the distance travelled by the sound is 2d.
$d _1=\frac{ v \times t _1}{2}$
Or, $d _1=\frac{336 \times 0.6}{2}=100.8 m$
And $d_2=\frac{v \times t_2}{2}$
Or, $d_2=\frac{336 \times 2.4}{2}=403.2 m$
$\therefore$ Total distance between two cliffs
$= d_1 + d_2 = (100.8 + 403.2)m = 504 m.$
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