Question

A person standing at a cliff shouts and hears the echo after 1.5 seconds. If the speed of
sound in air is 340 m/s, find the distance between the person and the cliff

Answer 1

Given that, a person standing at a cliff shouts and hears the echo after 1.5 seconds.

Let us assume that the distance between the person and the cliff is 'x'. As said in question that the echo is produced. Means the sound travelled from person to cliff and then cliff to person.

Therefore, the total distance covered by the sound is '2x'.

We have to find the distance ween the person and the cliff.

Now,

Distance = Speed × Time

We have, distance = 2x, speed of sound in air = 340 m/s (given) and time = 1.5 sec

Substitute the known values in the above formula

⇒ 2x = 340 × 1.5

⇒ 2x = 510

⇒ x = 510/2

⇒ x = 255 m

Therefore, the distance between the person and the cliff is 255 m.

Answer 2

Answer:

255 metres

Explanation:

Given:

• Time after which the echo was heard = 1.5 seconds
• Speed of sound in air = 340 m/s

To find:

• Distance between the person and cliff

Let us consider Distance as X,

As the echo has to go and come back, the distance will be equal to 2X

Distance = Speed×Time

2X = 340×1.5

2X = 510 m

$X=\frac{510}{2}$

X = 255 metres

Hence the distance between the person and the cliff is equal to 255 metres