Question

how is echo in a halls prevented? the sound of explosion on the surface of lake is heard by a boatman 100 m away and a driver 100 m below the point of explosion of the two person mentioned (boatman & driver) who would heard the sound first?

Answer 1

echo in the halls is prevented by placing sound absorbing object ssuch as sofa or cussions which reduces the echo boatman will hear first because sound travels faster in the air than liquid