一辆汽车以36km/h的速度向着山崖匀速行驶,途中鸣了一声笛,4秒钟后听到山崖传来回声,当司机听到回声时 一辆汽车以36千米每小时的速度匀速驶向一座大山,在某处鸣笛,...
\u4e00\u8f86\u6c7d\u8f66\u4ee536km/h\u7684\u901f\u5ea6\u671d\u5c71\u5d16\u5300\u901f\u884c\u9a76\uff0c\u5728\u79bb\u5c71\u5d16700m\u5904\u9e23\u7b1b\u540e\u6c7d\u8f66\u76f4\u7ebf\u5411\u524d\u884c\u9a76\u6bb5\u8def\u7a0b\u542c\u5230\u521a\u624d\u89e3\uff1av\u8f66\uff1d36km/h\uff1d10m/s
\u3000\u3000S\u8f66+S\u58f0\uff1d2L
\u3000\u3000v\u8f66t+v\u58f0t=2L
\u3000\u300010m/s x t+340m/s x t = 2 x 700m
\u3000\u3000t=4s
\u3000\u3000\u9e23\u7b1b\u540e4\u79d2\u542c\u5230\u56de\u58f0\uff0c\u6b64\u65f6\u6c7d\u8f66\u4e0e\u5c71\u5d16\u7684\u8ddd\u79bb\uff1a
\u3000\u3000S\uff1dL-S\u8f66\uff1dL-v\u8f66t\uff1d700m-10m/s x 4s=660m
\uff081\uff09\u6c7d\u8f66\u884c\u9a76\u7684\u901f\u5ea6\u4e3av=36km/h=10m/s\uff0c\u7531\u56fe\u53ef\u77e5\uff0c\u53f8\u673a\u542c\u5230\u56de\u58f0\u65f6\u8ddd\u79bb\u5c71\u5d16\u4e3aSBC\uff0c\u6839\u636e\u9898\u610f\u7531v=st\u5f97\uff0c10m/s\u00d74s+SBC=349m/s\u00d74s+10m/s\u00d74s2\uff0c\u89e3\u5f97SBC=660m\uff0e\uff082\uff09\u7531\u56fe\u53ef\u77e5\uff0c\u6c7d\u8f66\u9e23\u7b1b\u65f6\u79bb\u5c71\u5d16\u7684\u8ddd\u79bb\u4e3aAC\uff0c\u5373AB+BC\uff0c\u7531v=st\u5f97\uff0cSAB=vt=10m/s\u00d74s=40m\uff0c\u5219SAC=SAB+SBC=40m+660m=700m\uff0e\u7b54\uff1a\u6c7d\u8f66\u9e23\u7b1b\u65f6\u79bb\u5927\u5c71700m\uff0e
36km/h=10m/s设 鸣笛时距离山崖 L
340x4 + 10 x 4 =2L
L=700m
司机听到回声时离山:L- 10 x 4= =66m
若声速取340m/s
则4秒内通过的路程为4*340=1360m
36km/h=10m/s
所以汽车4秒通过的路程为10*4=40m
设还距x米,则
x+x+40=1360
x=1320/2
=660
不懂可追问,有帮助请采纳,谢谢!
汽车的速度v=36km/h=10m/s
听到回声时汽车运行的路程s=4*10=40m
声音往返的路程s!=340*4=1360m
则鸣笛时距离山L=(1360+40)/2=700
那么听到回声时距离山L!=700-40=660m
声速=340m/s 车速=36000/3600=10m/s
x+4*10=340*(4-x/340)
x=660m
绛旓細36km/h=10m/s 璁 楦g瑳鏃惰窛绂诲北宕 L 340x4 + 10 x 4 =2L L=700m 鍙告満鍚埌鍥炲0鏃剁灞憋細L- 10 x 4= =66m
绛旓細瑙o紝36KM/h=10M/s鍥涚鍚庨獞杞﹁椹朵簡4*10=40M 鈭靛0闊冲湪绌烘皵涓紶鎾熷害涓340M/S 鈭4绉掑0闊充紶鎾簡340X4=1360m 璁惧惉鍒板洖澹版椂璺濈灞卞礀鐨勮窛绂讳负x锛姹借溅楦g瑳鏃惰窛绂讳负Y锛屾牴鎹互涓婃潯浠堕偅涔堟垜浠彲浠ュ缓绔嬫柟绋:X+y=1340 y-x=40 瑙h繖涓簩鍏冧竴娆℃柟绋嬬殑x=650,y=690 绛:姹借溅楦g瑳鏃惰窛绂诲北宕690m锛屽惉鍒板洖澹...
绛旓細1)鍙戝姩鏈哄仛鐨勫姛=Pt=60kW*10min)=(60*1000W)*(10*60s)=3.6*10^7J 3.6*10鐨7娆℃柟鐒﹁ 2)鍖閫熺洿绾胯繍鍔,鐗靛紩鍔汧=闃诲姏f f=F=p/V V=36km/h=10m/s f=60*1000/10=6000N
绛旓細瑙o紝36KM/h=10M/s鍥涚鍚庨獞杞﹁椹朵簡4*10=40M 鈭靛0闊冲湪绌烘皵涓紶鎾熷害涓340M/S 鈭4绉掑0闊充紶鎾簡340X4=1360m 璁惧惉鍒板洖澹版椂璺濈灞卞礀鐨勮窛绂讳负x锛姹借溅楦g瑳鏃惰窛绂讳负Y锛屾牴鎹互涓婃潯浠堕偅涔堟垜浠彲浠ュ缓绔嬫柟绋嬶細X+y=1340 y-x=40 瑙h繖涓簩鍏冧竴娆℃柟绋嬬殑x=650, y=690 绛旓細姹借溅楦g瑳鏃惰窛绂诲北宕690m锛...
绛旓細36km/h=10m/s 姹借溅濡傛灉涓嶅埞杞︼紝浼氬湪15m / 10m/s = 1.5s 涔嬪悗鍒拌揪琛屼汉闈㈠墠锛岃繖鏃惰浜鸿蛋浜 1m/s * 1.5s =1.5m锛屼笉浼氬彂鐢熻溅绁
绛旓細锛1锛姹借溅琛岄┒鐨勯熷害涓簐=36km/h=10m/s锛岀敱鍥惧彲鐭ワ紝鍙告満鍚埌鍥炲0鏃惰窛绂诲北宕栦负SBC锛屾牴鎹鎰忕敱v=st寰楋紝10m/s脳4s+SBC=349m/s脳4s+10m/s脳4s2锛岃В寰桽BC=660m锛庯紙2锛夌敱鍥惧彲鐭ワ紝姹借溅楦g瑳鏃剁灞卞礀鐨勮窛绂讳负AC锛屽嵆AB+BC锛岀敱v=st寰楋紝SAB=vt=10m/s脳4s=40m锛屽垯SAC=SAB+SBC=40m+660m=700...
绛旓細Q鎬=cm c=4.6X10^7 m=24KG Q=4.6X10^7x24KG =1.104x10^9 Q鏈夛紳Q鎬籜畏 =1.104x10^9x30 =3.312X10^8 v=s/t v=36km/s s=100km t=100km/36km/h t=10000s P=W/t P=3.312X10^8/10000 =33120w 绛旓細鍔熺巼涓33120W ...
绛旓細姹借溅鐨勯熷害v 1 =36km/h=36脳 1 3.6 m/s=10m/s锛 璁鹃┚椹跺憳鎸夊枃鍙悗锛屽枃鍙0浼犲埌缁濆杩斿洖姹借溅鐢ㄧ殑鏃堕棿涓簍锛 鍦ㄦ椂闂磘鍐咃紝姹借溅琛岄┒鐨勮窛绂伙細 s 1 =v 1 t=10m/s脳t锛 澹伴煶浼犳挱鐨勮窛绂伙細 s 2 =v 2 t=340m/s脳t锛 璁炬寜鍠囧彮鏃舵苯杞﹀埌灞卞礀鐨勮窛绂讳负s锛 鐢遍鐭ワ紝2s...
绛旓細鐢遍鎰忕煡姹借溅鍋氬寑鍔犻熺洿绾胯繍鍔紝鍏秜0=36km/h=10m/s锛宎=2m/s2锛屽垯鏍规嵁鍖鍙橀熺洿绾胯繍鍔ㄧ殑浣嶇Щ鏃堕棿鍏崇郴x锛漹0t+12at2鐭ユ苯杞﹀湪5s鍐呭墠杩涚殑璺濈锛歺锛10脳5+12脳2脳52m锛75m鏁呴夛細B
绛旓細閫熷害鎹㈡垚m/s灏辨槸10m/s锛屽0閫熶负340m/s 鎸夊枃鍙悗澹伴煶鍒拌揪灞卞礀鐢ㄦ椂700/340=35/17s 姝ゆ椂姹借溅浣嶇Щ350/17m 涓庡北宕栫殑璺濈涓(700-350/17)m 鍓╀笅鐨勯棶棰樺氨鏄滅浉閬囬棶棰樷濅簡锛氬啀娆″惉鍒板洖澹扮殑鏃堕棿涓(700-350/17)/(340+10)=(2-1/17)s 姹借溅鍙堢Щ鍔ㄤ簡(20-10/17)m 鈭存鏃舵苯杞︾灞卞礀鐨勮窛绂讳负(700-...