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发表于 2019-9-13 23:46:11 | 显示全部楼层 |阅读模式
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???A?B????????v=2m/s?????P??A???????????C?????P??????????

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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?

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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

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