taraf intensitas bunyi senapan mesin 130 dB pd jarak 10 m. daya rata rata yg dikeluarkan senapan mesin tsb sebesar

Diket : Ti = 130 dB
r = 10 m
Dit : P......?
jawab : Ti = 10 log I / I○
130 = 10 log I / 10^-12
13 = log I 10^12
13 = log I + 12
13 - 12 = log I
1 = log I
I = 10

P = I . A
= 10 ( 4 phi 10^2 )
= 10 ( 4 3,14 100 )
= 10 4 314
= 12560 W