At a prayer meeting, the disciples sing JAI-RAM JAI-RAM. The sound amplified by a loudspeaker comes back after reflection from a building at a distance of 80 m from the meeting. What maximum time interval can be kept between one JAI.R4M and the next JAI-RAM so that the echo does not disturb a listener sitting in the meeting. Speed of sound in air is 320 m s-1

Given:


The distance of the building from the meeting = 80 m


Velocity of sound in air v= 320 m/sec


Total distance travelled by the sound after echo S= 80× 2 =160 m


We know that;




Therefore, the maximum interval of time will be 0.5 sec.


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