[填空题]
Workers around jet aircrh0 i ;ixuc))uufgw7w )a1 fn3qjo ux2gps(v4f6ypbxv-je8 3d 6 ft typically wear protective devices over their ears. Assume that the sound level of a jet airplane engine, at a distance of 30 m, is 140 dB, and that the average human ear has an effective radius of 2.0 cm. What would be the power intercepted by an unprotected ear at a distance of 30 m frvb18 2exj(3fdxp6j6 4-uf gvsy qnop3om a jet airplane engine? W
