During a spiritual gathering, the devotees chant HARE-RAM HARE-RAM. The sound is amplified by a loudspeaker and returns after reflecting from a building situated 80 m away from the gathering. Determine the maximum time interval that can be maintained between one HARE-RAM and the following HARE-RAM such that the echo does not disturb a listener seated in the gathering. The speed of sound in air is 320 m s ⁻¹ .

Step-by-step solution

The time taken for the sound to travel to the building and reflect back to the listener is given by t = 2d v Substituting the given values: t = 2 80 320 = 0.5 s For the echo not to disturb the listener, the reflected sound of the first chant must coincide with the chanting of the second one. If the time interval between the chants is greater than 0.5 s , the echo will be heard separately, causing a disturbance. Thus, the maximum time interval that can be maintained between consecutive chants is 0.5 s .