A person standing between two vertical cliffs produces the sound. Two successive echoes are heard at 4s and 6s. Calculate the distance between the cliffs. (Speed of sound in air = 320m/s)

The first cliff’s distance from the guy,

2\(\times \)D1 = velocity\(\times \)time

D1 = (320 \(\times \)4) / 2

D1 is equal to 640 metres.

D2 = (320 \(\times \) 6) / 2 is the distance between the second cliff and the person.

D2 = 960 metres

D1 + D2 = distance between cliffs

= 640 + 960

= 1600 m