一道难的初二物理题（一定要有过程，（1）的答案是5m/s,过程要（2） 一道初二物理题，急急急。。。求完整的过程和答案，有悬赏。

\u8981\u521d\u4e8c\u4e0a\u518c\u7269\u7406\u8ba1\u7b97\u9898100\u9053\uff0c\u542b\u89e3\u7b54\u8fc7\u7a0b\u548c\u7b54\u6848\u3000

\u4e00\u8f86\u6c7d\u8f66\u6cbf\u5e73\u76f4\u516c\u8def\u671d\u5c71\u5d16\u5300\u901f\u884c\u9a76\uff0c\u5728\u79bb\u5c71\u5d16s1\u5904\u9e23\u7b1b\uff0c\u6c7d\u8f66\u7ee7\u7eed\u5411\u524d\u884c\u9a76\uff0c\u6c7d\u8f66\u79bb\u9e23\u7b1b\u5904\u4e3as2\u65f6\uff0c\u53f8\u673a\u521a\u597d\u542c\u5230\u521a\u624d\u9e23\u7b1b\u7684\u56de\u58f0\uff0c\u5df2\u77e5s1:s2=12:1\uff0c\u58f0\u97f3\u5728\u7a7a\u6c14\u4e2d\u7684\u4f20\u64ad\u901f\u5ea6\u662f340m/s\uff0c\u6c42\u6c7d\u8f66\u884c\u9a76\u7684\u901f\u5ea6\u7684\u5927\u5c0f\uff08\u5728\u6574\u4e2a\u8fc7\u7a0b\u4e2d\uff0c\u6c7d\u8f66\u4e00\u76f4\u5728\u4f5c\u5300\u901f\u884c\u9a76\uff1b\u56de\u58f0\u7531\u5c71\u5d16\u53cd\u5c04\u9e23\u7b1b\u58f0\u6240\u5f62\u6210\uff09
\u89e3\uff1a\u56e0\u4e3as1\uff1as2=12\uff1a1,
\u3000\u3000\u6240\u4ee5S1=12S2\u58f0\u97f3\u4f20\u64ad\u7684\u8ddd\u79bb\uff1a
\u3000\u3000\u58f0= 2S1-S2=2*12S2-S2=23S2\uff0c
\u3000\u3000\u6240\u7528\u7684\u65f6\u95f4\uff1at=S\u58f0/v\u58f0=23S2/340
\u3000\u3000\u56e0\u6b64\u8f66\u901f\uff1aV\u8f66=S\u8f66/t= S2/(23S2/340)=340/23=14.78m/s
\u7b54\uff1a\u6c7d\u8f66\u884c\u9a76\u7684\u901f\u5ea6\u4e3a14.78m/s

\u4e00\u652f\u961f\u4f0d\u957f50m\uff0c\u4ee55m\u6bcf\u79d2\u7684\u901f\u5ea6\u901a\u8fc7\u4e00\u5ea7\u957f100m\u7684\u6865\uff0c\u4ece\u7b2c\u4e00\u4eba\u4e0a\u6865\u5230\u6700\u540e\u4e00\u4eba\u79bb\u5f00\u6865\u7528\u4e86\u591a\u5c11\u65f6\u95f4\uff1f
\u5df2\u77e5\uff1av=5m/s\uff0cS\u961f=50m\uff0cS\u6865\uff1d100m
\u6c42\uff1at
\u89e3\uff1at=S/v=(S+S)/v=(50m+100m)/5m/s=30s
\u7b54\uff1a\u4ece\u7b2c\u4e00\u4eba\u4e0a\u6865\u5230\u6700\u540e\u4e00\u4eba\u79bb\u5f00\u6865\u7528\u4e8630s\u7684\u65f6\u95f4

\u7532\u3002\u4e59\u4e24\u5730\u76f8\u8ddd162km\uff0c\u6c7d\u8f66\u4ee510m/s\u7684\u901f\u5ea6\u4ece\u7532\u5730\u51fa\u53d1\uff0c\u884c\u9a76\u4e8672\u5343\u7c73\u540e\uff0c\u63a5\u7740\u4ee545km/s\u7684\u901f\u5ea6\u884c\u9a76\u5230\u4e59\u5730\uff0c\u6c42\u6c7d\u8f66\u4ece\u7532\u5230\u4e59\u7684\u5e73\u5747\u901f\u5ea6
\u5df2\u77e5\uff1aS\uff1d162km\uff0cS1=72km v2=45km/h
\u6c42\uff1a\u5168\u7a0b\u7684\u5e73\u5747\u901f\u5ea6v\u89e3\uff1a10m/s=36km/hv=S/t=162/[72/36+(162-72)/45]=162/4=40.5(km/h)\u7b54\uff1a\u6c7d\u8f66\u4ece\u7532\u5230\u4e59\u7684\u5e73\u5747\u901f\u5ea6\u662f40.5km/h

\u4e00\u5217\u957f200\u7c73\u7684\u706b\u8f66\u4e0054\u5343\u7c73/\u65f6\u7684\u901f\u5ea6\u901a\u8fc7\u4e00\u4e2a\u957f700\u7c73\u7684\u5c71\u4e1c\u9700\u8981\u591a\u5c11\u65f6\u95f4?
\u7b54 4km/h=15m/s
t=s/v=(200+700)/15=60s

2.\u8774\u8776\u98de\u7fd4\u7684\u901f\u5ea6\u662f5\u7c73/\u79d2,\u8981\u975e\u5230\u8ddd\u51fa\u53d1\u70b90.6\u5343\u7c73\u7684\u82b1\u56ed,\u5b83\u8981\u82b1\u591a\u5c11\u65f6\u95f4?
\u7b54 t=s/v=600/5=120s

3.\u7532\u3001\u4e59\u4e24\u8f66\u5728\u540c\u4e00\u5e73\u76f4\u516c\u8def\u4e0a\u540c\u5411\u5f62\u5f0f,\u7532\u8f66\u901f\u5ea6\u4e3a10\u5343\u7c73/\u5c0f\u65f6,\u4e59\u8f66\u7684\u901f\u5ea6\u662f30\u5343\u7c73/\u5c0f\u65f6,\u4e59\u8f66\u53d1\u73b0\u5230\u8ffd\u4e0a\u7532\u8f66\u5f62\u5f0f\u4e8615\u5343\u7c73,\u6c42\u4e59\u8f66\u53d1\u73b0\u7532\u8f66\u65f6\u4e24\u8f66\u76f8\u8ddd\u591a\u5c11\u5343\u7c73
\u7b54 \u8bbe\u76f8\u8dddX.
t=15/10=1.5s
30*1.5=10*1.5+X

4.\u7532\u4e59\u4e24\u62b5\u76f8\u8ddd70\u5343\u7c73,\u4e00\u8f86\u6c7d\u8f66\u4ece\u7532\u5730\u5411\u4e59\u5730\u5f00\u51fa,\u901f\u5ea6\u662f15\u7c73/\u79d2,\u4e00\u8f86\u81ea\u884c\u8f66\u540c\u65f6\u4ece\u4e59\u5730\u51fa\u53d1\u9a76\u5411\u7532\u5730,\u4ed6\u4eec\u5728\u79bb\u7532\u573054\u5343\u7c73\u5904\u76f8\u9047.\u6c42\u81ea\u884c\u8f66\u7684\u901f\u5ea6\u662f\u591a\u5c11\u5343\u7c73/\u65f6
\u7b54 15m/s=54km/h
t=54/54=1h
v=s/t=(70-54)/1=16m/s

5.\u4e00\u8258\u5de1\u6d0b\u8230\u752870\u5343\u7c73/\u5c0f\u65f6\u7684\u901f\u5ea6\u8ffd\u8d76\u5728\u5b83\u524d\u976210\u5343\u7c73\u7684\u4e00\u8258\u6218\u6597\u8230,\u5de1\u6d0b\u8230\u8ffd\u4e86210\u5343\u7c73,\u6070\u597d\u8d76\u4e0a\u6218\u6597\u8230,\u6c42\u6218\u6597\u8230\u7684\u901f\u5ea6.
\u7b54 t=s/v=210/70=3h
\u8bbe\u901f\u5ea6\u4e3aV
210=3*V+10

6 \u7528\u4e00\u53ea\u73bb\u7483\u676f\u3001\u6c34\u548c\u5929\u5e73\u6d4b\u5b9a\u77f3\u5b50\u5bc6\u5ea6\uff0c\u5b9e\u9a8c\u8bb0\u5f55\u5982\u4e0b\uff1a\u676f\u5b50\u88c5\u6ee1\u6c34\u540e\u7684\u603b\u8d28\u91cfm1\uff1d200g\uff0c\u653e\u5165\u77f3\u5b50\u540e\uff0c\u676f\u5b50\u3001\u6c34\u3001\u77f3\u5b50\u603b\u8d28\u91cfm2\uff1d215g\uff0c\u53d6\u51fa\u77f3\u5b50\u540e\uff0c\u676f\u5b50\u548c\u6c34\u7684\u603b\u8d28\u91cf\u4e3am3\uff1d190g\uff0c\u6c42\u77f3\u5b50\u5bc6\u5ea6\u3002
\u7b54 m\u77f3=m2-m3=215g-190g=25g
v\u77f3=v\u6c34=\u5012\u51fa\u6c34\u7684\u8d28\u91cf/\u5012\u51fa\u6c34\u7684\u5bc6\u5ea6=200g-190g/1g/cm3=2.5g/cm3

7 \u7532\u4e59\u4e24\u540c\u5b66\u5206\u522b\u5728\u4e00\u8ddf\u94c1\u7ba12\u4fa7\uff0c\u94c1\u7ba1\u957f153\u7c73\uff0c\u7532\u5728\u5176\u4e00\u7aef\u6572\u51fb\u4e86\u4e00\u4e0b\uff0c\u4e59\u540c\u5b66\u542c\u89c1\u4e86\u4e24\u6b21\u58f0\u97f3\u3002\u5df2\u77e5\u542c\u5230\u4e24\u6b21\u58f0\u97f3\u7684\u95f4\u9694\u4e3a0.42\u79d2\u3002\u6c42\u58f0\u97f3\u5728\u94c1\u7ba1\u4e2d\u4f20\u64ad\u7684\u901f\u5ea6\u3002
\u89e3\uff1aT\u7a7a=S\u7a7a\u00f7V\u7a7a=153M\u00f7340M/S=0.45S
T\u94c1=T\u7a7a-0.42S=0.45S-0.42S=0.03S
V\u94c1=S\u00f7T\u94c1=153M\u00f70.03S=5100M/S
\u7b54\uff1a\u58f0\u97f3\u5728\u94c1\u7ba1\u4e2d\u4f20\u64ad\u901f\u5ea6\u4e3a5100\u7c73/\u79d2\u3002

8 \u9898\u76ee\uff1a\u6709\u4e00\u5c71\u5ce1\u5bbd1200\u7c73\uff0c\u4e24\u65c1\u90fd\u662f\u7ad6\u76f4\u5f92\u58c1\uff0c\u6709\u4e00\u4eba\u5728\u5c71\u5ce1\u5185\u653e\u4e00\u67aa\uff0c\u5934\u4e24\u6b21\u56de\u58f0\u95f4\u96945\u79d2\uff0c\u5219\u4eba\u79bb\u4e24\u58c1\u7684\u8ddd\u79bb\u662f\u591a\u5c11\uff1f\uff08\u8bbe\u58f0\u901fv\uff1d340\u7c73\uff0f\u79d2\uff09
\u7b54\u6848\uff1a1025\u7c73\uff0c175\u7c73\u3002
\u89e3\uff1a\u8bbe\u8ddd\u79bb\u4e3as,1200-s
s/340-(1200-s)/340=1200
s=1025

9 \u6709\u4e00\u5c71\u5ce1\u5bbd1200\u7c73\uff0c\u4e24\u65c1\u90fd\u662f\u5ced\u58c1\u3002\u6709\u4eba\u5728\u5c71\u5ce1\u5185\u653e\u4e00\u67aa\uff0c\u4ed6\u542c\u5230\u5934\u4e24\u6b21\u56de\u58f0\u95f4\u96945\u79d2\uff0c\u6c42\u8fd9\u4e2a\u4eba\u79bb\u4e24\u5ced\u58c1\u7684\u8ddd\u79bb\u3002\uff08\u7a7a\u6c14\u4e2d\u58f0\u901f\u4e3a340m/s\uff09

\u89e3\uff1a\u8bbe\u4eba\u79bb\u4e00\u5ced\u58c1\u7684\u8ddd\u79bb\u4e3ax,\u79bb\u53e6\u4e00\u5ced\u58c1\u7684\u8ddd\u79bb\u4e3a1200-x
\u5219\u58f0\u97f3\u5230\u4e24\u5ced\u58c1\u5e76\u8fd4\u56de\u7684\u65f6\u95f4\u5206\u522b\u4e3a\uff1a2x/340,2(1200-x)/340.
\u7531\u9898\u610f\uff0c2x/340-2(1200-x)/340=5
\u89e3\u5f97x=1025,1200-x=175
\u6240\u4ee5\u4eba\u79bb\u4e24\u5ced\u58c1\u7684\u8ddd\u79bb\u5206\u522b\u4e3a1025\u7c73\u548c175\u7c73\u3002

10 \u4e00\u95e8\u53cd\u5766\u514b\u70ae\u7784\u51c6\u4e00\u8f86\u5766\u514b\uff0c\u5f00\u70ae\u540e\u7ecf\u8fc70.6s\u770b\u5230\u70ae\u5f39\u5728\u5766\u514b\u4e0a\u7206\u70b8\uff0c\u7ecf\u8fc72.1s\u542c\u5230\u7206\u70b8\u7684\u58f0\u97f3\uff0c\u6c42\u5927\u70ae\u8ddd\u5766\u514b\u591a\u5143\uff1f\u70ae\u5f39\u7684\u98de\u884c\u901f\u5ea6\u591a\u5927\uff1f
\u8ddd\u79bbS\uff1d2.1*340m=714m
\u7b54 \u98de\u884c\u901f\u5ea6\uff1av=S/t=714/0.6=1190m/s

1\u3001 \u4e00\u5757\u4f53\u79ef\u4e3a100\u5398\u7c733\u7684\u51b0\u5757\u7194\u5316\u6210\u6c34\u540e\uff0c\u4f53\u79ef\u5982\u4f55\u6539\u53d8\uff0c\u6539\u53d8\u591a\u5c11\uff1f
m = \u03c1V = 100cm^3 * 0.9g/cm^3 =90g -------\u51b0\u5757\u7684\u8d28\u91cf
V = m/\u03c1 = 90g / 1g/cm^3 = 90cm^3 -------\u878d\u5316\u540e\u8d28\u91cf\u4e0d\u53d8\uff0c\u7b97\u51fa\u6c34\u7684\u4f53\u79ef\u4e3a90cm^3(90ml)

2\u3001\u6709\u4e00\u7a7a\u74f6\u5b50\u8d28\u91cf\u662f50\u514b\uff0c\u88c5\u6ee1\u6c34\u540e\u79f0\u5f97\u603b\u8d28\u91cf\u4e3a250\u514b\uff0c\u88c5\u6ee1\u53e6\u4e00\u79cd\u6db2\u4f53\u79f0\u5f97\u603b\u8d28\u91cf\u4e3a200\u514b\uff0c\u6c42\u8fd9\u79cd\u6db2\u4f53\u7684\u5bc6\u5ea6\uff1f

3\u3001\u6709\u4e00\u8282\u6cb9\u8f66\uff0c\u88c5\u6ee1\u4e8630\u7c733\u7684\u77f3\u6cb9\uff0c\u4e3a\u4e86\u4f30\u7b97\u8fd9\u8282\u6cb9\u8f66\u6240\u88c5\u77f3\u6cb9\u7684\u8d28\u91cf\uff0c\u4ece\u4e2d\u53d6\u51fa\u4e8630\u5398\u7c733\u77f3\u6cb9\uff0c\u79f0\u5f97\u8d28\u91cf\u662f24.6\u514b\uff0c\u95ee\uff1a\u8fd9\u8282\u6cb9\u8f66\u6240\u88c5\u77f3\u6cb9\u8d28\u91cf\u662f\u591a\u5c11\uff1f

4\u3001\u6709\u4e00\u8d28\u91cf\u4e3a5.4\u5343\u514b\u7684\u94dd\u7403\uff0c\u4f53\u79ef\u662f3000\u5398\u7c733\uff0c\u8bd5\u6c42\u8fd9\u4e2a\u94dd\u7403\u662f\u5b9e\u5fc3\u8fd8\u662f\u7a7a\u5fc3\uff1f\u5982\u679c\u662f\u7a7a\u5fc3\uff0c\u5219\u7a7a\u5fc3\u90e8\u5206\u4f53\u79ef\u591a\u5927\uff1f\u5982\u679c\u7ed9\u7a7a\u5fc3\u90e8\u5206\u704c\u4e00\u534a\u6c34\uff0c\u5219\u7403\u7684\u603b\u8d28\u91cf\u662f\u591a\u5927\uff1f

\u5ea6\u7684\u6d4b\u91cf1\u3001\u539f\u7406\uff1a2\u3001\u91cf\u7b52\u7684\u4f7f\u7528\u7528\u91cf\u7b52\u53ef\u4ee5\u76f4\u63a5\u6d4b\u51fa\u6db2\u4f53\u7684\u4f53\u79ef\u3002\u6d4b\u91cf\u56fa\u4f53\u7684\u4f53\u79ef\u65f6\uff0c\u5219\u9700\u5148\u5012\u5165\u9002\u91cf\u7684\u6c34\uff08\u653e\u5165\u7269\u4f53\u540e\u8981\u80fd\u6ca1\u8fc7\u7269\u4f53\uff0c\u53c8\u8981\u4e0d\u8d85\u6700\u5927\u6d4b\u91cf\u8303\u56f4\uff09\uff0c\u8bfb\u51fa\u6c34\u9762\u5230\u8fbe\u7684\u523b\u5ea6V1\uff0c\u518d\u5c06\u7269\u4f53\u653e\u5165\u5e76\u4f7f\u5176\u6d78\u6ca1\uff0c\u8bfb\u51fa\u6b64\u65f6\u7684\u8bfb\u6570V2\uff0c\u5219\u8be5\u7269\u4f53\u7684\u4f53\u79ef\u4e3aV\uff1dV2\uff0dV1\uff0c\u6b64\u79cd\u65b9\u6cd5\u79f0\u4e3a\u6392\u6c34\u6cd5\u3002

\u4f8b3 \u4f53\u79ef\u4e3a30 cm3\uff0c\u8d28\u91cf\u4e3a178g\u7684\u7a7a\u5fc3\u94dc\u7403\uff0c\u5982\u679c\u5728\u5176\u7a7a\u5fc3\u90e8\u5206\u94f8\u6ee1\u94dd\uff0c\u95ee\u94dd\u7684\u8d28\u91cf\u4e3a\u591a\u5c11\uff1f \u8981\u6c42\u51fa\u7a7a\u5fc3\u90e8\u5206\u94f8\u6ee1\u7684\u94dd\u7684\u8d28\u91cf\uff0c\u53ef\u5229\u7528\u516c\u5f0fm\uff1d\u03c1V\u6c42\u5f97\uff0c\u4f46\u8fd9\u91cc\u7684\u5173\u952e\u662f\u6c42\u51fa\u94dd\u7684\u4f53\u79ef\u3002\u6839\u636e\u9898\u610f\u53ef\u77e5\uff0c\u94dd\u7684\u4f53\u79ef\u7b49\u4e8e\u94dc\u7403\u7a7a\u5fc3\u90e8\u5206\u7684\u4f53\u79ef\uff0c\u800c\u7a7a\u5fc3\u90e8\u5206\u7684\u4f53\u79ef\u7b49\u4e8e\u7403\u7684\u4f53\u79ef\u51cf\u53bb\u94dc\u7684\u4f53\u79ef\u3002\u25b3V\uff1dV\u7403\uff0dV\u94dc\uff1d30\u00d710\uff0d6 m3\uff0d2\u00d710\uff0d5 m3\uff1d1\u00d710\uff0d5 m3\uff1dV\u94ddm\u94dd\uff1d\u03c1\u94ddV\u94dd\uff1d2.7\u00d7103 kg/m3\u00d71\u00d710\uff0d5 m3\uff1d27g\u4e13\u9898\u70b9\u8bc4 \u672c\u9898\u7684\u5173\u952e\u662f\u5148\u7528\u94dd\u7684\u4f53\u79ef\u4e0e\u7a7a\u5fc3\u90e8\u5206\u7684\u4f53\u79ef\u76f8\u7b49\uff0c\u518d\u501f\u52a9\u4e8e\u5bc6\u5ea6\u7684\u53d8\u5f62\u516c\u5f0f\u6c42\u51fa\u3002

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2\u3001\u4e00\u7a7a\u70e7\u676f\u7684\u8d28\u91cf\u4e3a100g\uff0c\u5012\u8fdb50 cm3\u7684\u7164\u6cb9\u540e\u603b\u8d28\u91cf\u4e3a140g\uff0c\u5219\u7164\u6cb9\u7684\u5bc6\u5ea6\u662f___kg/cm3\uff1b\u82e5\u7528\u6389 \u7164\u6cb9\uff0c\u5219\u5269\u4e0b\u7684\u7164\u6cb9\u7684\u8d28\u91cf\u662f g\uff0c\u5bc6\u5ea6\u662f g/cm3

1\u3001\u4e00\u4e2a\u74f6\u5b50\u7684\u8d28\u91cf\u662f0.2 kg\uff0c\u88c5\u6ee1\u6c34\u65f6\u603b\u8d28\u91cf\u4e3a0.7 kg.\u5f53\u88c5\u6ee1\u53e6\u4e00\u79cd\u6db2\u4f53\u65f6\uff0c\u603b\u8d28\u91cf\u4e3a0.8 kg\uff0c\u5219\uff1a\uff081\uff09 \u6c42\u6b64\u6db2\u4f53\u7684\u5bc6\u5ea6\uff1b\uff082\uff09 \u82e5\u7528\u8fd9\u4e2a\u74f6\u5b50\u88c5\u5bc6\u5ea6\u4e3a0.8 g/cm3\u7684\u7164\u6cb9\uff0c\u6c42\u6700\u591a\u53ef\u88c5\u591a\u5c11\u5343\u514b\u7684\u7164\u6cb9\u3002
2\u3001\u4e00\u4e2a\u8d28\u91cf\u4e3a232g\u7684\u94dc\u94dd\u5408\u91d1\u7403\uff0c\u5176\u4e2d\u542b\u94dd54g\uff0c\u94dc\u7684\u5bc6\u5ea6\u4e3a\u03c1\u94dc\uff1d8.9 g/cm3\uff0c\u94dd\u7684\u5bc6\u5ea6\u4e3a\u03c1\u94dd\uff1d2.7\u00d7103 kg/m3\uff0c\u6c42\u5408\u91d1\u7403\u7684\u5bc6\u5ea6\u4e3a\u591a\u5c11\uff1f

\u53c2\u8003\u7b54\u6848\u4e00\u30011\u3001640 0.089 \uff08\u63d0\u793a\uff1a\u6c34\u7684\u4f53\u79ef\u77e5\u9053\uff0c\u76f8\u5f53\u4e8e\u74f6\u5b50\u7684\u5bb9\u79ef\u77e5\u9053\uff0c\u5728\u88c5\u5165\u9152\u7cbe\u7684\u65f6\u5019\uff0c\u9152\u7cbe\u7684\u5bc6\u5ea6\u77e5\u9053\uff0c\u5176\u4f53\u79ef\u7b49\u4e8e\u74f6\u5b50\u7684\u5bb9\u79ef\uff0c\u7531\u5bc6\u5ea6\u7684\u516c\u5f0f\u53ef\u4ee5\u6c42\u51fa\u9152\u7cbe\u7684\u8d28\u91cf\uff1b\u8fd8\u53ef\u4ee5\u6c42\u51fa\u6c34\u7684\u8d28\u91cf\uff0c\u6c34\u7ed3\u6210\u51b0\u540e\uff0c\u8d28\u91cf\u6ca1\u6709\u53d8\u5316\uff0c\u7531\u4e8e\u5bc6\u5ea6\u53d1\u751f\u4e86\u53d8\u5316\uff0c\u6240\u4ee5\u4f53\u79ef\u4e5f\u4f1a\u53d8\u5316\uff0c\u7531\u8d28\u91cf\u9664\u4ee5\u4f53\u79ef\u5c31\u53ef\u4ee5\u5f97\u5230\u51b0\u7684\u4f53\u79ef\u3002\uff09

\u7528\u4e86\u591a\u5e74\u7684\u94c5\u7403\uff0c\u5176\u8868\u9762\u78e8\u635f\u4e86\u4e00\u4e9b\uff0c\u672a\u53d1\u751f\u53d8\u5316\u7684\u662f\u94c5\u7403\u7684\uff08\uff09
A\uff0e\u8d28\u91cf B\uff0e\u4f53\u79ef C\uff0e\u5bc6\u5ea6 D\uff0e\u8868\u9762\u79ef
2\uff0e\u4e09\u4e2a\u540c\u6837\u5927\u5c0f\u3001\u8d28\u91cf\u76f8\u7b49\u7684\u7a7a\u5fc3\u7403\uff0c\u5b83\u4eec\u5206\u522b\u7531\u94dd\u3001\u94c1\u3001\u94dc\u5236\u6210\uff08 \uff09\uff0c\u7403\u7684\u7a7a\u5fc3\u90e8\u5206\u7684\u4f53\u79ef\u662f\uff08\uff09
A\uff0e\u94dd\u7403\u6700\u5c0fB\uff0e\u94c1\u7403\u6700\u5c0fC\uff0e\u94dc\u7403\u6700\u5c0fD\uff0e\u90fd\u4e00\u6837\u5927

1.\u5df2\u77e5v=0.8m/s,t=64s-4s=60s
\u5219h1=s=vt=0.8m/s x 60s=48m.
\u2235\u5300\u901f\u76f4\u7ebf\u8fd0\u52a8
\u2234F1=G1=600kg x 10N/kg=6000N
\u7531W=Fs\u5f97\uff1aW=F1h1=6000N x 48m=2.88x10^5J
2.\u4f9d\u9898\u610f\u5f97\uff1av2=(0.8+0)/2=0.4m/s
\u7531v=s/t\u5f97s=vt=0.4m/s x 4s=1.6m
\u7531W=Fs\u5f97F2=W/s=11520J/1.6m=7200N.
3.\u7531W=Fs\u5f97W\u603b=F1s1+F2s2=6000N x 48m+7200N x 1.6m=2.9952x 10^5J
\u7531P=W/t\u5f97\uff1aP=2.9952 x 10^5J / 64s=4680w.

解决本题关键是利用速度公式v=s/t和变形式t=s/v，在代入数据之前，单位要统一，其单位换算关系1min=60s，1m/s=3.6km/h．
解：（1）已知s1=4500m，t1=15min=900s，代入速度公式v=s/t=4500/900=5m/s；
（2）已知s2=2660m，v=36km/h=10m/s，代入公式t=s/v，得t2=2660/10=266s，
故△t=t1-t2=900s-266s=634s；
答：（1）22路公交车行驶过程中的平均速度是5m/s；
（2）74路公交车比22路公交车在地面行驶时省634s．

已知S22路=4500m=4.5km，T22路=15min=0.25h，S隧道=2660m=2.66km，V74路=36km/h
求：（1）V22路.（2）T22路-T74路
解：V22路=S22路/T22路=4.5km/0.25h=18km/h （还没我骑车快 — —）
T74路=S隧道/V74路=2.66km/（36km/h）≈0.074h≈4.4min
T22路-T74路=15min-4.4min=10.6min
答：（1）平均速度是18lm/h
（2）省10.6min

（1）s1=4500m，t1=15min=900s，代入速度公式v=s/t=4500/900=5m/s；
（2）s2=2660m，v=36km/h=10m/s，代入公式t=s/v，得t2=2660/10=266s，
t=t1-t2=900s-266s=634s
答 ：…………………………

解：（1）V=4500M/（15*60s）=5m/s
(2)36km/h=10m/s
2660m/(10m/s)=266s
900s-266s=634s
答：能比22路公交车在地面行驶时省634秒。

4500除以15 再比一下

鏈夋病鏈夎緝闅剧殑鍒濅簩鐗╃悊娴姏棰,璋㈣阿!
绛旓細C锛庨搧鐞涓瀹鏄疄蹇冪殑 D锛庢湪鐞冧竴瀹氭槸瀹炲績鐨 3銆佷竴鏉¤埞浠庢渤閲屽紑鍒版捣閲岋紝娴姏澶у皬___,鎺掑紑娑蹭綋鐨勪綋绉痏__銆傦紙濉滃彉澶р濄佲滃彉灏忊濇垨鈥滀笉鍙樷濓級绛旀锛1銆佺瓑浜 2銆丅 3銆佷笉鍙 鍙樺皬 涓夛細缁煎悎璁粌 涓锛氬～绌洪锛1锛庢皵鐞冮鍦ㄧ┖涓彈鍒帮伎锛匡伎鍔涘拰锛匡伎锛垮姏浣滅敤锛屽悇鍔涚殑鏂藉姏鐗╀綋鍒嗗埆鏄伎...

涓閬撳垵浜岀墿鐞嗛(鏄垵浜屼笂瀛︽湡鐗╃悊浜烘暀鐗堥忛暅閭ｄ竴璇鐨棰樼洰,鏈夌偣闅惧害鍝...
绛旓細鍑搁忛暅 鍦ㄩ槼鍏変笅浣垮嚫閫忛暅鐨勭劍鐐硅惤鍦ㄦ绾夸笂,鐑ф柇妫夌嚎

鎬!鍦ㄧ嚎绛!姹涓閬瓒呴毦,璁╀汉鎯崇牬澶鐨勫垵浜岀墿鐞嗛
绛旓細灏哛1 R2涓ゅ彧瀹氬肩數闃讳互鏌愮鏂瑰紡杩炴帴璧锋潵鎺ュ叆鐢佃矾,R1涓婃秷鑰楃殑鐢靛姛鐜囦负12W,R2娑堣楃殑鐢靛姛鐜囦负P2,鑻ュ皢瀹冧滑浠ュ彟涓绉嶆柟寮忚繛鎺ュ悗鎺ュ叆鐢佃矾,姝ゆ椂R1涓婃秷鑰楃殑鐢靛姛鐜囦负27W,R2涓婃秷鑰楃殑涓篜2',鍒橮2:P2'=___:___鍥犱负涓ょ數闃诲湪鐢佃矾涓殑杩炴帴鏂瑰紡鍙湁涓茶仈鍜屽苟鑱斾袱绉,鍥犱负涓茶仈鏃讹紝缁忚繃2鐢甸樆鐨勭數娴佷竴鑷达紝璁炬鏃剁數娴佷负I...

姹備竴涓鍒濅簩鐗╃悊闅鹃
绛旓細姹涓閬撳垵浜岀殑鐗╃悊闅鹃銆傝娑夊強鍒版粦杞佹诞鍔涖佹満姊版晥鐜,濡傛灉鍙互鍔犱笂鍘嬪己銆傝鏈夐毦搴︾殑!!!骞剁粰鍑虹瓟妗!!鎬ヨ!!鍙敤鍒濅簩鐨勭煡璇!!璋㈣阿!... 姹備竴閬撳垵浜岀殑鐗╃悊闅鹃銆傝娑夊強鍒版粦杞佹诞鍔涖佹満姊版晥鐜,濡傛灉鍙互鍔犱笂鍘嬪己銆傝鏈夐毦搴︾殑!!!骞剁粰鍑虹瓟妗!!鎬ヨ!!鍙敤鍒濅簩鐨勭煡璇!!璋㈣阿! 灞曞紑 ...

涓閬撳垵浜岀殑鐗╃悊闅鹃(濡傛灉鍥炵瓟寰楀ソ,鍙互鎻愰珮鎮祻)
绛旓細(1)浠庡畨鍏ㄦ柟闈㈣冭檻锛屽鏋滄病鏈夌數闃籖1锛220V鐢靛帇鍏ㄥ姞鍦ㄦ寚绀虹伅ND涓,鑰孨D鑰愬帇鍙湁6V,鎵浠,灏嗕細鍑虹幇鎸囩ず鐏鐑ф帀鐨勬晠闅;(2)鑻ユ寚绀虹伅ND閫夆6V 0.2A鈥濇櫘閫氱伅娉,鍒欐寚绀虹伅涓殑鐢垫祦I1=0.2A,璇ユ敮璺(鍖呮嫭R1)娑堣楀姛鐜囦负 P1=UI1=220V脳0.2A=44W 鑻ユ寚绀虹伅ND閫夆6V 10mA鈥濇櫘閫氱伅娉,鍒欐寚绀虹伅涓殑鐢垫祦I...

鎬!鎬!鎬!瀵绘壘鍒濅簩鏈闅剧殑鐗╃悊棰樼洰!
绛旓細鎴戞湁鍑犻亾:鏈2涓钩闈㈤暅鍨傜洿,鍦ㄨ繖涓棿鏈変竴鍙戝厜鐐筍闂竴鍏辨垚鍑犱釜璞 绛旀鏄3涓 (鍏朵腑鏈変竴涓槸2閲嶅拰鐨,杩欎釜灏辩畻涓涓)杩樻湁鏄:娌歌吘娓╁害涓嶅彉鐨勫師鍥?钂稿彂娓╁害涓嬮檷鐨勫師鍥.绛旀:娌歌吘杩囩▼瑕佷笉鏂粠澶栫晫鍚告敹鐑噺,铏界劧鍔ㄨ兘杈冨ぇ鐨勫垎瀛愰稿嚭,浣嗗張浠庡鐣岃ˉ鍏呬簡鑳介噺,娑蹭綋鍒嗗瓙鐨勫钩鍧囧姩鑳戒笉鍙,娓╁害淇濇寔涓嶅彉.钂稿彂鏄...

涓閬鎴戞劅瑙夋瘮杈闅剧殑鍒濅簩鐗╃悊棰
绛旓細瑙: 鎴戝氨鐞嗚В鎴愭湁涓ゆ缁冲瓙鎷垮姩婊戣疆浜嗗搱 鈶 W鏈夛紳Gh锛漨gh锛50kg脳10N/kg脳2m锛1000J 鈶 璁炬诲叡涓篨 畏锛漌鏈/W鎬 鈭碬鎬伙紳1000J/0.7 锛漍 鈭碭锛滷S 鍙互绠楀嚭F鐨勫.鏈夋牴鎹甈锛滷V. P鐭ラ亾浜.F鐭ラ亾浜.灏卞彲浠ョ畻鍑洪熷害浜 (鍥犱负纭疄娌℃潅涓湅鎳備綘鐨勫浘.鎴戝氨璁や负鏄袱娈电怀瀛愭媺鍔ㄦ粦杞簡鍝....

闂涓閬撳垵浜鍏充簬澶ф皵鍘鐨勭墿鐞嗛(寰毦)
绛旓細濡傛灉鏄摱鍙ｇ珫鐩存湞涓嬬殑璇濓紝鍙鏄搧鐡跺瓙娌℃湁瑁傞殭銆佸畬濂芥棤鎹熺殑璇濓紝鐞嗚涓婃槸涓婊存按涔熻繘涓嶅幓銆傞殢鐫娣卞害鐨勫鍔狅紝浣犵湅鍒扮摱瀛愰噷鏈夋按锛屾槸鍥犱负闅忕潃娣卞害鐨勫鍔狅紝姘寸殑鍘嬪己鍦ㄥ鍔狅紝褰撴按鐨勫帇寮哄ぇ浜庝竴涓ぇ姘斿帇鏃讹紝鐡跺唴灏变細杩涘幓涓閮ㄥ垎姘达紝浣跨摱鍐呯殑绌烘皵鍘嬬缉锛屾皵浣撶殑鍘嬪己澧炲姞锛屼簩鑰呮墠鑳藉钩琛★紝濡傛灉浣犳妸鐡跺瓙涓婂崌锛岀摱瀛愬唴鐨...

涓閬撳垵浜岀墿鐞嗛,闅惧掍竴澶х墖,澶у杩囨潵绛斾竴涓!
绛旓細褰撶劧鏄疍缁冲瓙~鎷夊姏灞炰簬杩戣窛鐢电鍔 蹇呴』鎺ヨЕ 鍦扮悆灞炰簬杩欎釜鍔涚殑鏈鍒濆師鍥 骞朵笉鏄柦鍔涚墿浣

鎼滈泦鍒濅簩鐨勭墿鐞娴姏棰100閬,瑕闅剧殑,鍔犱笂璇︾粏鐐圭殑瑙ｆ瀽,鏈夊繀瑕佺殑璇濋厤鍥...
绛旓細鍦ㄢ滄姉娲姠闄┾濅腑锛屽嚑浣嶅悓瀛︽壘鍒颁簡涓寮犳讳綋绉负0.3 m3鐨勮川閲忓垎甯冨潎鍖鐨勯暱鏂逛綋濉戞枡娉℃搏搴婂灚锛屽皢鍏舵斁鍏ュ叾涓椂锛屽簥鍨湁1/5浣撶Н娴告病鍦ㄦ按涓傛眰锛氾紙1锛夋鏃跺簥鍨彈鍒扮殑娴姏澶氬ぇ銆傦紙2锛夊簥鍨殑瀵嗗害銆傦紙3锛夎嫢琚晳鐨勪汉鏄钩鍧囪川閲忎负50kg锛岃淇濊瘉瀹夊叏锛屽垯璇ュ簥鍨笂涓娆℃渶澶氳兘鎵胯浇澶氬皯浜恒傦紙g=10N/kg锛夊湪绌烘皵...

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