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...
绛旓細dB锛屽叏绉鍒嗚礉锛屾槸涓涓箍娉涘簲鐢ㄤ簬宸ョ▼棰嗗煙鐨勭函璁℃暟鍗曚綅銆傚湪鍔熺巼娴嬮噺涓紝dB鐨勮绠楀叕寮忔槸 dB = 10 * log(鍔熺巼姣)锛岃繖閲岀殑"鍔熺巼姣"閫氬父鏄袱涓姛鐜囧肩殑姣斿笺備緥濡傦紝濡傛灉浣犵殑璁惧鍔熺巼鎻愬崌浜10鍊嶏紝鍔熺巼姣斿氨鏄10锛岄偅涔堝鐩婂氨鏄 10 dB銆傚浜庣數鍘嬫垨鐢垫祦杩欑被淇″彿锛宒B鐨勫畾涔夋湁鎵涓嶅悓锛屽畠閲囩敤鐨勬槸 dB = 20...
绛旓細鍦ㄥ疄闄呭簲鐢ㄤ腑锛屾瘮濡傝绠椾袱涓０闊冲己搴︾殑鍋忓樊锛岀櫨鍒嗘暟褰㈠紡鍜屽垎璐濆舰寮忓彲浠ョ浉浜掕浆鎹傚鏋滀綘鐨勫０鍘嬬骇鍋忓樊鍦ㄧ櫨鍒嗘暟褰㈠紡琛ㄧず涓-20%~+30%锛屽搴旂殑鍒嗚礉鍊煎氨鏄-20dB~+30dB銆傚叕寮忓涓嬶細鐧惧垎鏁板亸宸浆鍖栦负鍒嗚礉鍋忓樊锛 -x dB = -20 * log10(1 - (a% / 100))鍒嗚礉鍋忓樊杞寲涓虹櫨鍒嗘暟鍋忓樊锛 y dB = 20 * log...
绛旓細3銆鍒嗚礉鐨勫鐩/琛板噺锛坉B澧炵泭/dB琛板噺锛夛細dB=10*log10(Pout/Pin)銆傚叾涓紝Pout鏄緭鍑轰俊鍙风殑鍔熺巼锛孭in鏄緭鍏ヤ俊鍙风殑鍔熺巼銆備竴銆乨b鐨勫畾涔 db锛屽嵆鍒嗚礉锛坉ecibel锛夛紝鏄竴绉嶈〃绀虹墿鐞嗛噺鐩稿姣斾緥鍏崇郴鐨勫崟浣嶏紝甯哥敤浜庢祴閲忓０闊炽佷俊鍙峰拰鍔熺巼绛夈傚垎璐濇槸浠ュ鏁版瘮渚嬬殑鏂瑰紡鏉ヨ〃杈句袱涓墿鐞嗛噺涔嬮棿鐨勫樊寮傘傚湪澹板涓紝鍒嗚礉鐢ㄤ簬...
绛旓細鍒嗚礉鏄竴绉嶅害閲忓０闊冲己搴︾殑鍗曚綅锛屽畠鍩轰簬瀵规暟鍒诲害琛ㄧず澹伴煶鐨勫搷搴︺傚叿浣撹绠楁柟娉曚緷璧栦簬澹板帇绾х殑鍙樺寲锛岄氬父閲囩敤浠ヤ笅鍏紡鏉ヨ绠楋細dB = 20 脳 log10 鍏朵腑锛歞B浠ｈ〃鍒嗚礉鏁般侾1浠ｈ〃鐩爣澹伴煶鐨勫０鍘嬬骇銆侾0鏄竴涓弬鑰冨０鍘嬬骇锛岄氬父涓哄熀鍑嗗硷紝閫氬父鏄┖姘斾腑澹板帇鐨勪竴涓浐瀹氬笺俵og10琛ㄧず浠10涓哄簳鐨勫鏁拌繍绠椼傚垎璐濈殑璁＄畻...
绛旓細鍒嗚礉锛坉B锛鏄竴绉嶆祴閲忓姛鐜囨垨鍦洪噺鐩稿澶у皬鐨勫崟浣嶏紝鍏朵腑1dB浠ｈ〃鍔熺巼鎴栧満閲忕殑姣斿煎彉鍖栦负10:1銆傚浜庡姛鐜囬噺锛屽闊冲己鎴栬兘閲忓瘑搴︼紝鍏跺垎璐濆艰绠楀叕寮忎负dB = 10 x log10(A/B)锛屽叾涓瑼鍜孊鏄袱涓姛鐜囧笺備緥濡傦紝鑻鐨勫姛鐜囨槸B鐨1.25892鍊嶏紝鍒欏畠浠浉宸1dB銆傝屽満閲忥紝濡傜數鍘嬫垨鐢垫祦锛屽叾鍒嗚礉瀹氫箟鏄痙B = 10 ...
