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(2)2.
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1?(??)???????m??????????v0???????????A??????????
????????????B????????t0?????????? ( )?
A???????????????????????????B??????t0
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C???????????????????(????)v?v0???
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D???????????????????(????)v>v0??????????????????B????????t0
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A?t2???????A????????
B?t2????????????????????
C?0?t2?????????????????????
D?0?t3?????????????????????
3.?????????????v1????????P?Q?????????????????t?0??P??????????v2?P??????????t?t0??P?????????????????????????????P?????????????(
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A???????? B????????
C??????????? D???????????
5.?????????????AB????L???????????????
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(??????????????) ( )? 4???m?????????????????????????????????????????
A?????B?????v??????????????
B????????????g(sin ???cos ?)??L?????????????v?????
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D????????????A?B??????????a>gsin ?
6??????????????A?B???????L???????????????????????v?????????????????????????A?????????????????????????????????????????g??????A?B??????????( )
A?????B?????v????????????????
B????????????g(sin ???cos ?)??L???????????v??
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C????tan ??????A??B???????????
D????????????A??B??????????????a?gsin ?
7.????????????????????????37 ???????4 m????????0.45 m???????3 m/s???????????????????A??????????????????????B?????????3 m/s????????????????????????????????0.5??g?10 m/s2?sin 37?0.6?cos 37?0.8???
(1)??A????????????????
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8.??????????????v?????????????m?????????v??????????????????????????????????????????????????????????????????????????W??????????????????Q???????????( )
A.W?0?Q?mv2 B.W?0?Q?2mv2
mv2C.W?Q?mv2 D.W?mv2?Q?2mv2 2
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D?W1>W2?P1?P2?Q1?Q2
10.????????????????????????????C????C???????????????????????v??????????????????A??????????????????????????????????????????????????????????????????v?????m??????????
A????v???????????????
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11.?????????????????????????????????????????????h?????????????v??????????????????????????????????????????????????m???????????????tan??????????????????????????????? ? ???????????????????
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4.??????????
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A?a1?2 m/s2?a2?3 m/s2
B?a1?3 m/s2?a2?2 m/s2
C?a1?5 m/s2?a2?3 m/s2
D?a1?3 m/s2?a2?5 m/s2
3.?????A???B?????m?10 kg???A????B??L?3 m????A?B??????A?????????B???????????A?B?B????????????????1?0.3??2?0.1?g?10 m/s2?
(1)???A?????B??????A???????
(2)????B??????????A??(1)???????B??????????A???B?????A?B????????
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1.?????????????????F????????????????????????????0~t1????????????????( ) A.????????????????? B.????????? C.??????????? D.??????????
2.???A?B???????????????????A?B????????????????A?B?????????????A????m???????A??????????????
3.??????????4N???????????????????????????????????????????????30???????????????????????????????????????????????( ) A.??4N B.??3NC.??1ND.??
4.???????????????????????l=8m????????m=10kg?????v0=10m/s????????????????????????????????=0.6?g?10m/s2????????????????????
(1)????????????????A??????B?????????? (2)???????v=4m/s????????????????????A???B??????
(3)???????v=4m/s???????????????????????A???B???????????????????????
5.????????????????????????????????????3-7-6?????????????????????AB????v=1m/s????????????m=4kg?????????A?????????????????=0.1?AB????l=2m?g?10m/s2?
?1??A???B???????????????????
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6.?14????????????????????v1????????P?Q?????????????????t = 0??P??????????v2?P??????????t = t0??P?????????????????????????????P????????????????
7???3-7-9??????30???????????2m/s?????AB?5m??1kg?????A???2.9s??B?????????????????????????????????A???B???????????g=10m/s2?
8.??3-7-5????????m=1kg??????M=10kg????????????????????=0.5?????????????????F=90N?????????v0=4m/s?????????????????????????l?????? ??g=10m/s2?
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t1=1s?v?=2m/s?????????????
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a3?t?t1?2=2?1m
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2
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N??A?B??????????f2=F????2N<F
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222
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v
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2s
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11
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22
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a1t?a2t?L?v0?v??a1t
22
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????????? 1????????????????AB?sAB=2m?BC???????=37???sBC =4m?????P???????????=0.25?
???A?B????????v=2m/s?????P??A???????????C?????P??????????
A?????C????????sin37=0.6?g=l0m/s2?
2?????????????????abc. ????ab?????????=37?bc?????????=53?ab?????4.7m?bc?????3.5m. ?????m=1kg????A??????????????????=0.8. ????????????v=1m/s????. ????A???a??????????c????????A???????.?sin37=0.6?sin53=0.8?g=10m/s2?
????A?a?????b???????
c3??14????????????????????????????????????????A?B????3m?????????????????C, D????4. 45m?B, C??????????5m/s?????????????????10kg????????????A?????????B?????????????????C??????????????????0. 5?g?10m/s2?sin37?=0. 6?cos37?=0. 8
(1)?CD????????
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