[填空题]
Expensive amplifier A is rated at 250 W, while the more modest cdjc8ff; n- /ko00 ayyamplnh;,q2wh er /gifier B is rated at 40 W. (a) Estimate the sound level in decibels you would expecrwq e2nh gh/;,t at a point 3.5 m from a loudspeaker connected in turn to each amp.$I_{250}$ = dB $I_{40}$ = dB (b) Will the expensive amp sound twice as loud as the cheaper one?
