Question

A man stands at a distance from a cliff and claps his hands. He receives an echo from the cliff after 4 s. Calculate the distance between the man and the cliff. Assume the speed of sound to be 343 ms-1.'

Answer 1

Answer:

The distance between the man and the cliff is 43.75 m

Answer 2

Given:-

→ Time after which the man receives the

echo = 4s

→ Speed of sound = 343m/s

To find:-

→ Distance between the man and the cliff.

Solution:-

We know that :-

If 'd' is the distance of the man from the cliff, then the total distance travelled by the wave in time interval 't' is '2d'.

∵ Speed = Distance/Time

=> v = 2d/t

=> vt = 2d

∴ d = vt/2

By substituting values in the above equation, we get :-

=> d = 343×4/2

=> d = 343×2

=> d = 686m

Thus, distance between the man and the cliff is 686m .

Some Extra Information:-

Ultrasound : Any sound of frequency higher than 20000 Hertz is called ultrasound.

(a) Ultrasound is also known as

ultrasonic waves.

(b) Human beings are ultrasound deaf.

(c) Ultrasound is produced by a

specialized instrument called

electronic oscillator.