An observer stands at a distance of $850 m$ from the cliff and fires a gun. After what time gap will he hear the echo, if sound travels at a speed of $350 m s^{- 1}$ in air?

$6.89 s$

No worries! We‘ve got your back. Try BYJU‘S free classes today!

$4.00 s$

No worries! We‘ve got your back. Try BYJU‘S free classes today!

$2.93 s$

No worries! We‘ve got your back. Try BYJU‘S free classes today!

$4.86 s$

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

Open in App

Solution

The correct option is D
$4.86 s$

Given:
Speed of sound, $v = 350 m s^{- 1}$
Distance between the observer and the cliff, $d = 850 m$

Distance travelled $s = 2 d$
because sound travels from the observer to the cliff and back to the observer.

$Speed = \frac{Distance}{Time}$
$v = \frac{2 d}{t}$
$t = \frac{2 d}{v}$
$t = \frac{2 \times 850}{350} = 4.86 s$

Suggest Corrections

Similar questions

An observer stands at a distance of $850 m$ from the cliff and fires a gun. After what time will he hear the echo of gunfire if sound travels at a speed of $350 m s^{- 1}$ in the air?

A man stands at a distance of 68 m from a cliff and fires a gun.
The time interval after which will he hears the echo is:

[Take the speed of sound in air is 340 m s-1]

Q. (a) What is an echo ? How is echo formed ?
(b) What is the minimum distance in air required from a sound reflecting surface to hear an echo (at 20°C) ?
(c) A man standing 825 metres away from a cliff (steep rock) fires a gun. After how long will he hear its echo ? Speed of sound in air is 330 m/s.

Join BYJU'S Learning Program

An observer stands at a distance of 850 m from the cliff and fires a gun. After what time gap will he hear the echo, if sound travels at a speed of 350ms−1 in air?

The correct option is D 4.86 s Given: Speed of sound, v=350 ms−1 Distance between the observer and the cliff, d=850 m Distance travelled s=2d because sound travels from the observer to the cliff and back to the observer. Speed=DistanceTime v=2dt t=2dv t=2×850350=4.86 s

An observer stands at a distance of $850 m$ from the cliff and fires a gun. After what time gap will he hear the echo, if sound travels at a speed of $350 m s^{- 1}$ in air?