log~~(dB)分贝.....
公式: L=10 log I/I底数0 3&4题取i(右下方 *** all0) =10^-12 W/m^2 3. 已知在的士高所量度的声音响度为120dB
求声音的强度.
答案:1W/m^2 120 = 10 log ( I /10^-12 W/m^2) 12 = log ( I /10^-12 W/m^2) ( I /10^-12 W/m^2) = 10^12 I =10^-12 W/m^2 x 10^12 (not 10^-12 x 10^12 = 10^0 = 1) I = 1 W/m^2 4.在午膳时
中四甲班的声音响度为65dB.求该班的声音强度(答 案准确至2位有效数字)...............答案:3.2x10^-6 W/m^2 65 = 10 log ( I /10^-12 W/m^2) 6.5 = log ( I /10^-12 W/m^2) ( I /10^-12 W/m^2) = 10^6.5 I =10^-12 W/m^2 x 10^6.5 I =10^-5.5 W/m^2 I = 3.16 x10^-6 W/m^2 I = 3.2 x10^-6 W/m^2 (案准确至2位有效数字) 10.在音乐会&足球场所录得的声音响度分别为80dB&85dB.求足球场的声音强度与音乐会的声音强度之比为多少?...............答案:3.2:1 85 = 10 log ( I(85) /10^-12 W/m^2) 8.5 = log ( I(85) /10^-12 W/m^2) I(85) =10^-12 W/m^2 x 10^8.5 80 = 10 log ( I(85) /10^-12 W/m^2) 8.0 = log ( I(85) /10^-12 W/m^2) I(80) =10^-12 W/m^2 x 10^8.0 The ratio I(85)/I (80) [10^-12 W/m^2 x 10^8.5]/[10^-12 W/m^2 x 10^8.0] [10^8.5]/[ 10^8.0] 10^(8.5 – 8.0) 10^0.5 3.16 比为3.2 / 1
绛旓細绛旀:1W/m^2 120 = 10 log ( I /10^-12 W/m^2) 12 = log ( I /10^-12 W/m^2) ( I /10^-12 W/m^2) = 10^12 I =10^-12 W/m^2 x 10^12 (not 10^-12 x 10^12 = 10^0 = 1) I = 1 W/m^2 4.鍦ㄥ崍鑶虫椂 涓洓鐢茬彮鐨勫0闊冲搷搴︿负65dB.姹傝鐝殑澹伴煶寮哄害(...
绛旓細dB鐨勬剰涔夊叾瀹炲啀绠鍗曚笉杩囦簡锛屽氨鏄妸涓涓緢澶э紙鍚庨潰璺熶竴闀夸覆0鐨勶級鎴栬呭緢灏忥紙鍓嶉潰鏈変竴闀夸覆0鐨勶級鐨勬暟姣旇緝绠鐭湴琛ㄧず鍑烘潵銆傚锛堟澶勪互鍔熺巼涓轰緥锛夛細X = 100000 = 10*log(10^5) = 50 dB銆乆 = 0.000000000000001 = 10*log(10^-15) = -150 dB銆DB鐨勫叾浠栧惈涔夛細1銆db鏄鍒嗚礉鐨勬剰鎬濓紝鏄0闊冲崟浣嶃
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绛旓細10*log()銆傚浜庣數鍘嬫垨鐢垫祦锛dB = 20*log()銆俤B鐨勬剰涔夊叾瀹炲啀绠鍗曚笉杩囦簡锛屽氨鏄妸涓涓緢澶э紙鍚庨潰璺熶竴闀夸覆0鐨勶級鎴栬呭緢灏忥紙鍓嶉潰鏈変竴闀夸覆0鐨勶級鐨勬暟姣旇緝绠鐭湴琛ㄧず鍑烘潵銆傚锛堟澶勪互鍔熺巼涓轰緥锛夛細X = 100000 = 10*log(10^5)= 50 dB X = 0.000000000000001 = 10*log(10^-15)= -150 dB dBm...
绛旓細db鏄鍒嗚礉鐨勬剰鎬濄傚垎璐濇槸閲忓害涓や釜鐩稿悓鍗曚綅涔嬫暟閲忔瘮渚嬬殑璁¢噺鍗曚綅锛屼富瑕佺敤浜庡害閲忓0闊冲己搴︼紝甯哥敤dB琛ㄧず銆傗滃垎鈥濇寚鍗佸垎涔嬩竴锛屼釜浣嶆槸鈥滆礉鈥濓紙bel锛夛紝涓鑸彧閲囩敤鍒嗚礉銆傗滆礉鈥濇槸鈥滆礉灏斺濈殑绠绉帮紝鏄互鏉板嚭绉戝瀹禔lexanderGrahamBell鐨勫悕瀛楁潵鍛藉悕鐨勫崟浣嶃傝礉灏斿湪1876骞磋幏寰椾簡鐢佃瘽鍙戞槑鐨勪笓鍒╋紝骞跺湪鐢佃瘽鐨勫簲鐢ㄥ拰鍙戝睍涓...
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