A man shouts loudly close to a high wall. He hears an echo. If the man is at 40 m from the wall, how long after the shout will the echo be heard?
(speed of sound in air = 330 m/s)
Given: s = 40m, v = 330 m/s
To Find: time (t)
Formula: Time = distance \(\frac{distance}{speed}\)
Calculation:
The distance travelled by the sound wave
= 2 × distance from man to wall.
= 2 × 40 = 80 m.
From formula,
∴ Time taken to travel the distance
\(\frac{distance}{speed}=\frac{80}{30}\) = 0.24 s