一、单选题:本大题共<strong><span>7</span></strong>小题,共<strong><span>28</span></strong>分。
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1.
下列说法正确的是( )
A . 布朗运动是在显微镜下看到的液体分子的无规则运动
B . 给自行车胎打气,越打越费力是因为分子间存在斥力
C . 随着两分子间距离的增大,可能出现分子势能增大而分子间的作用力减小的过程
D . 气体在
时每个分子的动能都大于其在
时的动能
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4.
如图所示,a、b两束单色光分别沿不同方向射向横截面为半圆形玻璃砖的圆心O,已知a光刚好发生全反射, b光的折射光线
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%28%3C%2Fmo%3E%3C%2Fmath%3E)
反射光线未画出
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmath%3E)
刚好与a光的反射光线重叠,且
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%B1%3C%2Fmi%3E%3Cmo%3E%26gt%3B%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%B2%3C%2Fmi%3E%3C%2Fmath%3E)
, 则判断( )
![](//tikupic.21cnjy.com/2024/04/28/d0/9f/d09fc1878b7ba2ce4a9752949976874e.png)
A . 若将b光沿a光的光路射向O点, b光也能发生全反射
B . 用a、b单色光分别检查同一光学平面的平整度时, b光呈现的明暗相间的条纹要窄些
C . 在玻璃砖中,a光的波速比b光大
D . 用a、b单色光分别以相同入射角斜射入同一平行玻璃砖,a光发生的侧移大
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6.
用高压水枪清洗汽车的照片如图所示,设水枪喷出的水柱截面为圆形,直径为 D,水流速度为 v,水柱垂直汽车表面,水柱冲击汽车后反方向的速度为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0.2%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Ev%3C%2Fmi%3E%3C%2Fmath%3E)
, 高压水枪的质量为 M,手持高压水枪操作,已知水的密度为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3E%CF%81%3C%2Fmi%3E%3C%2Fmath%3E)
。下列说法正确的是( )
![](//tikupic.21cnjy.com/2024/04/28/3e/13/3e139768d911afb96a0820a52d9625ee.png)
A . 水柱对汽车的平均冲力为
B . 高压水枪单位时间喷出的水的质量为
C . 当高压水枪喷口的出水速度变为原来2倍时,水柱对汽车的平均冲力加倍
D . 高压水枪喷出水柱直径D减半时,水柱对汽车的压强变小
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7.
输电能耗演示电路如图所示,左侧变压器原、副线圈匝数比为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmo%3E%3A%3C%2Fmo%3E%3Cmn%3E6%3C%2Fmn%3E%3C%2Fmath%3E)
, 输入电压为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E7.5%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3EV%3C%2Fmi%3E%3C%2Fmath%3E)
的正弦交流电。连接两理想变压器的导线总电阻为r,负载 R的阻值为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E10%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%A9%3C%2Fmi%3E%3C%2Fmath%3E)
。开关S接1时,右侧变压器原、副线圈匝数比为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmo%3E%3A%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmath%3E)
, R上的功率为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E40%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3EW%3C%2Fmi%3E%3Cmo%3E%3B%3C%2Fmo%3E%3C%2Fmath%3E)
接2时,匝数比为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmo%3E%3A%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmath%3E)
, R上的功率为P。以下判断正确的是( )
![](//tikupic.21cnjy.com/2024/04/28/43/aa/43aa5c7d913b07189098e81093dcf8a3.png)
二、多选题:本大题共<strong><span>3</span></strong>小题,共<strong><span>12</span></strong>分。
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8.
下列有关光学现象说法正确的是( )
![](//tikupic.21cnjy.com/2024/04/28/ff/b8/ffb89cd4782ae7619f1017a8faa2dd4a.png)
A . 图1为检验工件平整度的装置,利用了光的衍射原理
B . 图2为光照射透光的小圆孔得到的干涉图样
C . 图3中沙漠蜃景属于光的全反射现象,其产生的原因是沙漠上层空气的折射率比下层空气的折射率大
D . 图4中电影院的3D电影利用了光的偏振
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9.
如图所示为一款玩具“弹簧公仔”,该玩具由头部、轻弹簧及底座组成,已知公仔头部质量为 m,弹簧的劲度系数为k,底座质量为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0.5%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
。压缩公仔头部,然后由静止释放公仔头部,此后公仔头部在竖直方向上做简谐运动,重力加速度为 g。当公仔头部运动至最高点时,底座对桌面的压力刚好为零,弹簧始终在弹性限度内。则下列说法正确的是( )
![](//tikupic.21cnjy.com/2024/04/28/35/fc/35fc91159accc0a1178d06dcb8a63ac6.png)
A . 公仔头部做简谐运动的振幅为
B . 公仔头部运动至最高点时,头部的加速度为 g
C . 公仔头部有最大速度时,弹簧处于原长
D . 公仔头部运动至最低点时,桌面对底座支持力的大小为3 mg
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10.
如图所示,质量为M的带有四分之一光滑圆弧轨道的小车静止置于光滑水平面上,圆弧的半径为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3ER%3C%2Fmi%3E%3Cmo%3E%28%3C%2Fmo%3E%3C%2Fmath%3E)
未知
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmath%3E)
, 一质量为m的小球以速度
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3Ev%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
水平冲上小车,恰好达到圆弧的顶端,此时M向前走了
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E0.25%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3ER%3C%2Fmi%3E%3C%2Fmath%3E)
, 接着小球又返回小车的左端。若
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EM%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
, 重力加速度为 g,则( )
![](//tikupic.21cnjy.com/2024/04/28/f5/8e/f58ebe22969d078f47a965ebfdcab37d.png)
A . 整个过程小车和小球组成系统动量和机械能都守恒
B . 圆弧的半径为
C . 小球在弧形槽上上升到最大高度所用的时间为
D . 整个过程小球对小车做的功为
三、实验题:本大题共<strong><span>2</span></strong>小题,共<strong><span>18</span></strong>分。
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11.
某同学在做“测定玻璃折射率”的实验时已经画好了部分图线,如图甲所示,并在入射光线 AO上插上大头针
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
、
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
, 现需在玻璃砖下表面折射出的光线上插上
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
和
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EP%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E4%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
大头针,便能确定光在玻璃砖中的折射光线。
![](//tikupic.21cnjy.com/2024/04/28/e6/eb/e6eb41e1bfa6b96082a7350b2544ce11.png)
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(2)
经过多次测量作出
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Ei%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3En%3C%2Fmi%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%B8%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%E2%88%92%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Ei%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3En%3C%2Fmi%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%B8%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3C%2Fmath%3E)
的图像如图乙,玻璃砖的折射率为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%3B%3C%2Fmo%3E%3Cmo%3E%28%3C%2Fmo%3E%3C%2Fmath%3E)
保留三位有效数字
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12.
某学习小组用三枚相同的硬币来验证动量守恒定律。将两枚硬币叠放粘连,记为 A,另一枚硬币记为 B,在水平桌面左端固定一弹射装置,PQ为中轴线,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3E%27%3C%2Fmi%3E%3C%2Fmath%3E)
与轴线垂直作为参考线。实验步骤如下:
![](//tikupic.21cnjy.com/2024/04/28/25/5f/255fff0b881096560b6339d613635684.png)
①如图甲,将A从P沿PQ弹射,A停止后,测出其右端到
的距离![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3ES%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3B%3C%2Fmo%3E%3C%2Fmath%3E)
②如图乙,将B静置于轴线上,并使其左端与
相切;
③如图丙,将A压缩弹簧至同甲位置,射出后在
处与B正碰,A、B停止后,测出A右端和B左端到
的距离
、
。
请回答以下问题:
-
(1)
两次从同一位置弹射A,目的是确保 A到达
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3EO%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3E%27%3C%2Fmi%3E%3C%2Fmath%3E)
线时具有相同的
。
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(3)
多次实验,若测量数据均近似满足关系式
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%28%3C%2Fmo%3E%3C%2Fmath%3E)
用题中给定符号表达
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmath%3E)
, 则说明硬币碰撞过程中动量守恒。
四、计算题:本大题共<strong><span>3</span></strong>小题,共<strong><span>30</span></strong>分。
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13.
一列简谐横波在介质中沿x轴正方向传播,波长不小于8 cm。如图所示, P和M是介质中平衡位置分别位于
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Ex%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmath%3E)
和
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Ex%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E4%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Ec%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
处的两个质点。
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Et%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0%3C%2Fmn%3E%3C%2Fmath%3E)
时开始观测,此时质点 P的位移为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Ey%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E5%3C%2Fmn%3E%3Cmsqrt%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmsqrt%3E%3Cmi+mathvariant%3D%22normal%22%3Ec%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
, 质点M处于平衡位置,此时两质点均向y轴正方向振动
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmo%3E%3B%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3Et%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmfrac%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E4%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3C%2Fmath%3E)
时,质点P第一次到达波峰位置,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Et%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmfrac%3E%3Cmrow%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E4%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmfrac%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3C%2Fmath%3E)
时,质点 M第一次到达波峰位置。求:
![](//tikupic.21cnjy.com/2024/04/28/08/ca/08ca26122514a4f5fd6be3fc98e8c56c.png)
-
-
-
14.
合理利用自然界中的能源是一个重要的课题。在我国某海域,人们设计了一个浮桶式波浪发电灯塔。如图甲所示,该浮桶由内、外两密封圆筒构成,浮桶内磁体由支柱固定在暗礁上,内置
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EN%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E100%3C%2Fmn%3E%3C%2Fmath%3E)
的线圈。线圈与阻值
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3ER%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E14%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%A9%3C%2Fmi%3E%3C%2Fmath%3E)
的灯泡相连,随波浪相对磁体沿竖直方向上下运动且始终处于磁场中,其运动速度
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Ev%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmsqrt%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmsqrt%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Ei%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3En%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3E%CF%80%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Et%3C%2Fmi%3E%3Cmo%3E%28%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3Cmo%3E%2F%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3Cmo%3E%29%3C%2Fmo%3E%3C%2Fmath%3E)
。辐向磁场中线圈所在处的磁感应强度大小
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.2%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3ET%3C%2Fmi%3E%3C%2Fmath%3E)
。单匝线圈周长
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3EL%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E1.5%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
, 线圈总电阻
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Er%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E1%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%A9%3C%2Fmi%3E%3C%2Fmath%3E)
, 圆形线所在处截面如图乙所示。求:
![](//tikupic.21cnjy.com/2024/04/28/17/c7/17c7a17d47b29ca42e396d14edb46b49.png)
-
-
(2)
灯泡工作时消耗的电功率
-
(3)
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E3%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Ei%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3En%3C%2Fmi%3E%3C%2Fmath%3E)
内发电灯塔消耗的电能。
-
15.
如图所示,长为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EL%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
的水平传送带以
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Ev%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3Cmo%3E%2F%3C%2Fmo%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3C%2Fmath%3E)
的速度匀速转动,紧靠传送带两端的水平面上各静止一个物块 B和C,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EB%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EC%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E1.0%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Ek%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Eg%3C%2Fmi%3E%3C%2Fmath%3E)
。在距传送带左端
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.5%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
的水平面上放置一竖直固定弹性挡板,物块与挡板碰撞后会被原速率弹回,右端有一倾角为
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E37%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%E2%88%98%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3C%2Fmath%3E)
且足够长的粗糙倾斜轨道de,斜面底端与传送带右端平滑连接。现从距斜面底端
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EL%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E2%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmath%3E)
处由静止释放一质量
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3EA%3C%2Fmi%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.6%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Ek%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Eg%3C%2Fmi%3E%3C%2Fmath%3E)
的滑块A,一段时间后物块 A与B发生弹性碰撞,碰撞时间忽略不计,碰撞后 B滑上传送带, A被取走。已知物块B、C与传送带间的动摩擦因数
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%BC%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E1%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.2%3C%2Fmn%3E%3C%2Fmath%3E)
, 与水平面间的动摩擦因数
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%BC%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.02%3C%2Fmn%3E%3C%2Fmath%3E)
, 物块A与斜面间的动摩擦因数
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmsub%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3E%CE%BC%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E3%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsub%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.25%3C%2Fmn%3E%3C%2Fmath%3E)
, 物块间的碰撞都是弹性正碰,不计物块大小,g取
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmn%3E10%3C%2Fmn%3E%3Cmi+mathvariant%3D%22normal%22%3Em%3C%2Fmi%3E%3Cmo%3E%2F%3C%2Fmo%3E%3Cmsup%3E%3Cmrow%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmn%3E2%3C%2Fmn%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3C%2Fmath%3E)
。
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Ei%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3En%3C%2Fmi%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E37%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%E2%88%98%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.6%3C%2Fmn%3E%3C%2Fmath%3E)
,
![](//math.21cnjy.com/MathMLToImage?mml=%3Cmath+xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F1998%2FMath%2FMathML%22%3E%3Cmi+mathvariant%3D%22normal%22%3Ec%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Eo%3C%2Fmi%3E%3Cmi+mathvariant%3D%22normal%22%3Es%3C%2Fmi%3E%3Cmsup%3E%3Cmrow%3E%3Cmn%3E37%3C%2Fmn%3E%3C%2Fmrow%3E%3Cmrow%3E%3Cmo%3E%E2%88%98%3C%2Fmo%3E%3C%2Fmrow%3E%3C%2Fmsup%3E%3Cmo%3E%3D%3C%2Fmo%3E%3Cmn%3E0.8%3C%2Fmn%3E%3C%2Fmath%3E)
。求:
![](//tikupic.21cnjy.com/2024/04/28/e1/f6/e1f6ae3df4b4680bb5456f67f5624cbb.png)
-
(1)
物块A与物块B相碰前物块A的瞬时速度大小;
-
(2)
物块B与物块C第一次碰撞前,物块B在传送带上滑行过程中因摩擦产生的内能;
-