Sample problem 19-2 Spherical sound waves are emitted uniformly in all directions from a point source, the radiated power P being 25 w. What are the intensity and the sound level of the sound wave at a distance r=2. 5m from the source? Solution 251 =0.32w/m 4m24x(2.5m) Sz=1010g/ 0.32v/m =10 log 115dB 102w/mSample problem 19-2 Spherical sound waves are emitted uniformly in all directions from a point source, the radiated power P being 25 w. What are the intensity and the sound level of the sound wave at a distance r=2.5m from the source? Solution: 2 2 2 0.32 / 4 (2.5 ) 25 4 w m m w r P I = = =   dB w m w m I I SL 115 10 / 0.32 / 10log 10log 1 2 2 2 0 = = = −