V Part A At a rock concert, a dB meter registered 130 dB when placed 2.9 m in front of a loudspeaker on the stage. The intensity of the reference level required to determine the sound level is What was the power output of the speaker, assuming uniform spherical spreading of the sound and neglecting absorption in the air? 1.0 x 10-12 W/m2 Express your answer to two significant figures and include the appropriate units. P = Value Units Submit Request Answer V Part B How far away would the sound level be 89 dB ? Express your answer to two significant figures and include the appropriate units. Value Units Submit Request Answer P PearsonPart A What was the power output of the speaker, assuming uniform spherical spreading of the sound and neglecting absorption in the air? Express your answer to two significant figures and include the appropriate units. HA P = 1.0 . 105 W You have already submitted this answer. Enter a new answer. No credit lost. Try again. Submit Previous Answers Request AnswerSofn a Using the formula B = 10 log. I. at 8 = 2.9m B = 130 dB . Therefore 130 I log. 13 = Log -12 I 13 I 5/ 2 I = low Im 2 at 8= 2.gm. Then , Since P = IA = 1OXY TY2 1 0x 4 7 ( 2 - 9 ) 2 W P = 1. 1 X 105 W so the Power output of the speaker is 1.1 X10. W, ( Using two Significant figures ) .b Intensity Corresponding to 89dB of Sound level is, B = lolog ( I 89 = log. 12 12 08 ( 10 ) - I 10 12 I = 7 . 9 4 3 X 10 W / M 2 Now , Byusing , P = IA P = I (4 x82) P UTI P 7Yx I -7 8 = | 47 ( 7 . 9 43 X 10Y ) m of 7=10.10 3 x 10 m = 3. 3 X 10 mSo the Sound well be 89 2B, at distance, 3.3 X10 m 2 away from the loudspeaker on the stage, Using two significant figures)