[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"$f4k00L1wU5alpL9c7Vrf52RwtkzYpt1rHBXTqBGmNNPU":3},{"answer":4,"createTime":5,"id":6,"options":7,"origin":12,"question":19,"related":20,"source":24,"type":25},[],"2023-05-16 13:30:10",12916106,[8,9,10,11],"9 N·s","-9 N·s","10 N·s","-10 N·s",{"count":13,"courseId":14,"courseImg":15,"courseName":16,"workId":17,"workName":18},13,"837939070e66b4a1b9971c2b88982cf1","https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fc4c491a4bf65856aa9400a6bdf60473f.jpg","大学物理","d4517e828c684b2096c31339a766b87a","2.2 动量守恒定律","质量为20 g的子弹沿X轴正向以 500 m\u002Fs的速率射入一木块后,与木块一起仍沿X轴正向以50 m\u002Fs的速率前进,在此过程中木块所受冲量的大小为",[21,26,35,44,53,63,72,81,90,99],{"answer":22,"createTime":5,"id":6,"options":23,"question":19,"source":24,"type":25},[],[8,9,10,11],"v1",0,{"answer":27,"createTime":5,"id":28,"options":29,"question":34,"source":24,"type":25},[],12916107,[30,31,32,33],"0.267 N","16 N","240 N","14400 N","机枪每分钟可射出质量为20 g的子弹900颗,子弹射出的速率为800 m\u002Fs,则射击时的平均反冲力大小为",{"answer":36,"createTime":5,"id":37,"options":38,"question":43,"source":24,"type":25},[],12916108,[39,40,41,42],"A的动量增量的绝对值比B的小","A的动量增量的绝对值比B的大","A、B的动量增量相等","A、B的速度增量相等","质量分别为mA和mB (mA>mB)、速度分别为\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F3cb2e64e3e3231535d43d47e4a6aacbb.png\"> 和\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F200818027bb6b5a12020f9f80e49df3a.png\"> (vA> vB)的两质点A和B,受到相同的冲量作用,则",{"answer":45,"createTime":5,"id":46,"options":47,"question":52,"source":24,"type":25},[],12916109,[48,49,50,51],"mv","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fa3983a6cead9d2a6364f1f738f90f909.png\">mv","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F9a06b89f35066c7341073ca25d0f1e9f.png\">mv","2mv","质量为m的质点,以不变速率v沿图中正三角形ABC的水平光滑轨道运动.质点越过A角时,轨道作用于质点的冲量的大小为 \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fe95baa550fbc8e65ceb0867187917475.png\">",{"answer":54,"createTime":5,"id":55,"options":56,"question":62,"source":24,"type":25},[],12916110,[57,58,59,60,61],"vA = 0,vB = 0","vA = 0,vB > 0","vA < 0,vB > 0","vA < 0,vB = 0","vA > 0,vB > 0","A、B两条船质量都为M,首尾相靠且都静止在平静的湖面上,如图所示.A、B两船上各有一质量均为m的人,A船上的人以相对于A船的速率u跳到B船上,B船上的人再以相对于B船的相同速率u跳到A船上. 取如图所示x坐标,设A、B船所获得的速度分别为vA、vB,下述结论中哪一个是正确的? \u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F37c2ae9a9e04a2a87a1895c338a1d1f2.png\">",{"answer":64,"createTime":5,"id":65,"options":66,"question":71,"source":24,"type":25},[],12916111,[67,68,69,70],"比原来更远","比原来更近","仍和原来一样远","条件不足,不能判定","一炮弹由于特殊原因在水平飞行过程中,突然炸裂成两块,其中一块作自由下落,则另一块着地点(飞行过程中阻力不计)",{"answer":73,"createTime":5,"id":74,"options":75,"question":80,"source":24,"type":25},[],12916112,[76,77,78,79],"总动量守恒","总动量在炮身前进的方向上的分量守恒,其它方向动量不守恒","总动量在水平面上任意方向的分量守恒,竖直方向分量不守恒","总动量在任何方向的分量均不守恒","在水平冰面上以一定速度向东行驶的炮车,向东南(斜向上)方向发射一炮弹,对于炮车和炮弹这一系统,在此过程中(忽略冰面摩擦力及空气阻力)",{"answer":82,"createTime":5,"id":83,"options":84,"question":89,"source":24,"type":25},[],12916113,[85,86,87,88],"2 m\u002Fs","3 m\u002Fs","5 m\u002Fs","6 m\u002Fs","一质量为60 kg的人起初站在一条质量为300 kg,且正以2 m\u002Fs的速率向湖岸驶近的小木船上,湖水是静止的,其阻力不计.现在人相对于船以一水平速率v沿船的前进方向向河岸跳去,该人起跳后,船速减为原来的一半,v应为",{"answer":91,"createTime":5,"id":92,"options":93,"question":98,"source":24,"type":25},[],12916114,[94,95,96,97],"\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F0da47551f628fabc3d2633d3ef0d35d9.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fde41ace83ef11669a8c9f6af92b3671d.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F947368391aa1906f3f393eb1b1c86096.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F48b75522330298e820dd5d9c34200d75.png\">","一竖直向上发射之火箭,原来静止时的初质量为m0经时间t燃料耗尽时的末质量为m,喷气相对火箭的速率恒定为u,不计空气阻力,重力加速度g恒定.则燃料耗尽时火箭速率为",{"answer":100,"createTime":5,"id":101,"options":102,"question":107,"source":24,"type":25},[],12916115,[103,104,105,106],"\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F4f830e200b0f2c82a752e2e521978e7c.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F6767ac6c780634c7cefae0971c9073f8.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002F7ce6b6fa6816e030f2479b6c81d14a84.png\">","\u003Cimg src=\"https:\u002F\u002Ftihai-oss-cloud.itihey.com\u002Fimg\u002Fa07298e0de4dc5cb38f6214189bb07ac.png\">","某喷气式飞机以v0的速率在空气中水平飞行时,引擎吸入的空气和燃料混合燃烧后生成的气体相对于飞机以速率u向后喷出.设喷气机原有质量为M、消耗燃料的质量为dm,同时吸入空气的质量为dm1,则对于飞机(含燃料)和吸入空气组成的系统而言,动量守恒方程在水平方向(前进方向为正)的投影式为"]