Question:

A boy standing between two cliffs claps and hear two echoes, the first after 2 seconds and the second after 3 seconds. The velocity of sound is 360 m/sec. The distance in meter between the two cliffs is

Updated On: Jun 7, 2022
  • 900
  • 360
  • 1400
  • 1200
Hide Solution
collegedunia
Verified By Collegedunia

The Correct Option is A

Solution and Explanation

Here boy is standing at point O between cliff (i) and (ii) $d_1$ and $d_2$ be the distances of boy to cliff (i) and (ii) respectively and let $v_s$ be the velocity of sound.
$\therefore \:\: d_1 = \frac{v_s \times t_1}{2} $ and $d_2 = \frac{v_s \times t_2}{2}$


Total distance $d = d_1 + d_2$
$= \frac{v_S \times t_1}{2} + \frac{v_s \times t_2}{2} $
$= \frac{v_s ( t_1 +t_2)}{2} = \frac{360}{2} \times (2 + 3) = 900 \, m$
Was this answer helpful?
0
0

Concepts Used:

Waves

Waves are a disturbance through which the energy travels from one point to another. Most acquainted are surface waves that tour on the water, but sound, mild, and the movement of subatomic particles all exhibit wavelike properties. inside the most effective waves, the disturbance oscillates periodically (see periodic movement) with a set frequency and wavelength.

Types of Waves:

Transverse Waves -

Waves in which the medium moves at right angles to the direction of the wave.

Examples of transverse waves:

  • Water waves (ripples of gravity waves, not sound through water)
  • Light waves
  • S-wave earthquake waves
  • Stringed instruments
  • Torsion wave

The high point of a transverse wave is a crest. The low part is a trough.

Longitudinal Wave -

A longitudinal wave has the movement of the particles in the medium in the same dimension as the direction of movement of the wave.

Examples of longitudinal waves:

  • Sound waves
  • P-type earthquake waves
  • Compression wave