A point source of power 50π watts is producing sound waves of frequency 1875Hz. The velocity of sound is 330m/*, atmospheric pressure is 1.0 x 105Nm-2, density of air is 1.0kgm-3. Then pressure amplitude at r = 330 m from the point source is (using π = 22/7):
(A) 5 Nm-2
(B) 10 Nm -2
(C) 15 Nm -2
(D) 20 Nm-2
