2026届北京海淀区高三物理4月联考模拟试卷（含答案详解与评分标准）第261套

高三物理4月联考模拟试卷2026届北京海淀区高三物理4月联考模拟试卷（含答案详解与评分标准）第261套学校：________________班级：________________姓名：________________考号：________________考试时间：90分钟满分：150分注意事项：1．本试卷用于4月联考阶段性综合检测，覆盖力学、电磁学、热学、光电与实验等主干内容，要求在规定时间内独立完成。2．答题前请将学校、班级、姓名、考号填写清楚；选择题将答案填在题后括号内，填空题直接写出结果，解答题写出必要文字说明、方程和演算过程。3．计算题中未特别说明时，取重力加速度g＝10m/s²；数值结果保留合适有效数字，单位不可缺省。4．全卷共22题。选择题12题，共60分；填空题4题，共20分；解答题6题，共70分。一、选择题（本题共12小题，每小题5分，共60分）说明：1—8题为单项选择题，每题只有一个选项正确；9—12题为多项选择题，每题至少有两个选项正确，全部选对得5分，选对但不全得3分，有错选或不选得0分。1．一辆试验小车沿直线运动，0—4s内速度由0均匀增大到12m/s，4—7s内保持12m/s不变，7—10s内速度均匀减小到0。下列说法正确的是（）A．0—4s内小车的加速度大小为2m/s²B．0—10s内小车的位移为78mC．7—10s内小车的平均速度为12m/sD．全过程小车的平均速率为6.6m/s答：________2．某同学从距水平地面1.25m高的实验台边缘水平抛出一小球，小球离开台面时速度为5.0m/s，不计空气阻力。小球落地瞬间的速度大小最接近（）A．5.0m/sB．6.0m/sC．7.1m/sD．10.0m/s答：________3．某人造卫星绕地球做半径为r、周期为T的匀速圆周运动。只利用r、T和引力常量G，可求得地球质量M。下列关系正确的是（）A．M＝4π²r³/(GT²)B．M＝GT²/(4π²r³)C．M＝4π²r/(GT²)D．M＝GT²r/(4π²)答：________4．光滑水平面上，质量为0.40kg的小车A以3.0m/s的速度向右运动，与静止的质量为0.20kg的小车B发生一维弹性碰撞。碰后小车B获得的动量大小为（）A．0.40kg·m/sB．0.60kg·m/sC．0.80kg·m/sD．1.20kg·m/s答：________5．两块足够大的平行金属板间电压为300V，间距为5.0cm。一电子从负极板附近由静止释放，不计重力和边缘效应。电子到达正极板附近时动能增加量为（）A．5eVB．60eVC．300eVD．1500eV答：________6．长为0.50m的直导线垂直悬于匀强磁场中，导线中通有2.0A电流。磁感应强度大小为0.40T，导线与磁场方向夹角为30°。导线所受安培力大小为（）A．0.10NB．0.20NC．0.35ND．0.40N答：________7．面积为2.0×10⁻²m²的单匝闭合线圈放在垂直于线圈平面的匀强磁场中。磁感应强度在0.30s内由0均匀增大到0.60T，线圈总电阻为0.40Ω。感应电流大小为（）A．0.020AB．0.050AC．0.10AD．0.40A答：________8．劲度系数为50N/m的轻弹簧连接质量为0.50kg的小球，小球在光滑水平面上做简谐运动，振幅为10cm。小球通过平衡位置时的速度大小为（）A．0.50m/sB．1.0m/sC．2.0m/sD．5.0m/s答：________9．一定质量的理想气体在体积不变的条件下被缓慢加热。下列判断正确的是（）A．气体对外做功为0B．气体内能减小C．气体压强增大D．单位时间内气体分子撞击器壁的平均作用效果增强答：________10．如图示意电路可等效为理想电源、定值电阻R₁和滑动变阻器R₂串联。保持电源电动势不变，不计导线电阻。当滑片使R₂阻值增大时，下列说法正确的是（）A．电路总电流减小B．R₁两端电压增大C．电源输出的总电功率减小D．R₂两端电压一定减小答：________11．用频率高于截止频率的单色光照射某金属表面，发生光电效应。下列说法正确的是（）A．增大入射光强度，光电子最大初动能增大B．增大入射光强度，单位时间逸出的光电子数通常增多C．减小入射光频率但仍高于截止频率，遏止电压增大D．增大入射光频率，光电子最大初动能增大答：________12．一根两端固定的弦线上形成稳定驻波，波速不变。下列说法正确的是（）A．相邻波节间距离等于半个波长B．基频大小为v/(2L)，其中L为弦长C．各点同时经过平衡位置时速度方向一定相同D．允许的振动频率为基频的整数倍答：________二、填空题（本题共4小题，每小题5分，共20分）13．用两只光电门测小车的匀加速直线运动。遮光片宽度为2.00cm，小车通过光电门1、2的遮光时间分别为0.040s和0.025s，两光电门间距0.30m，则小车的加速度大小为________m/s²。答：____________________________________________________________________14．电容为20μF的电容器接在200V的直流电源两端，稳定后电容器所带电荷量为________C，储存的电场能为________J。答：____________________________________________________________________15．一个100匝线圈中穿过每匝的磁通量在0.020s内均匀减少3.0×10⁻⁴Wb，则线圈中产生的平均感应电动势大小为________V；若回路电阻为5.0Ω，平均感应电流为________A。答：____________________________________________________________________16．某热机每个循环从高温热源吸收800J热量，向低温热源放出500J热量，则每个循环对外做功为________J，热效率为________。答：____________________________________________________________________三、解答题（本题共6小题，共70分）要求写出必要的文字说明、方程式和重要演算步骤。只写出最后答案而无过程的，不得分；有数值计算的题，答案必须明确单位。17．（10分）一列地铁列车从站台由静止出发，前8.0s做匀加速直线运动，速度达到16m/s；随后以16m/s匀速行驶20s；接着以大小为2.0m/s²的加速度匀减速刹车至停止。求：

（1）列车加速阶段的加速度大小；

（2）列车从出发到停止的总位移；

（3）全过程的平均速率。作答区：________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________18．（10分）水平平行金属板长0.50m，板间形成竖直向下的匀强电场，电场强度大小为1.5×10³N/C。质量为2.0×10⁻³kg、带电荷量为+4.0×10⁻⁶C的小球以5.0m/s的水平速度从板间中线射入，重力需要计入且取g＝10m/s²。小球在板间运动过程中未碰到极板。求：

（1）小球的竖直加速度大小和方向；

（2）小球离开极板区域时竖直方向的位移；

（3）电场力对小球所做的功。作答区：________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________19．（12分）某实验小组利用气垫导轨研究碰撞过程。滑块A、B在同一直线上运动，已知mA＝0.30kg，mB＝0.20kg。碰前A向右运动，B静止；碰后A仍向右运动，B也向右运动。光电门测得速度如下表。项目碰前vA/(m·s⁻¹)碰前vB/(m·s⁻¹)碰后vA′/(m·s⁻¹)碰后vB′/(m·s⁻¹)测量值1.2000.401.18（1）计算碰撞前、后的系统总动量，并判断在实验误差允许范围内动量是否守恒；

（2）计算碰撞前、后的系统机械动能，并判断该碰撞是否可视为弹性碰撞；

（3）写出两条减小本实验系统误差的措施。作答区：________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________20．（12分）两根平行金属导轨间距为0.50m，处在竖直向下的匀强磁场中，磁感应强度为0.40T。金属杆PQ垂直导轨放置并与导轨接触良好，导轨左端接有电阻R＝0.80Ω，除R外其他电阻不计。

（1）若金属杆以2.0m/s的速度向右匀速运动，求感应电动势、回路电流和金属杆所受安培力大小；

（2）若对静止金属杆施加恒定水平拉力F＝0.30N，使其从静止开始向右运动，不计摩擦，求金属杆最终能达到的稳定速度；

（3）说明稳定速度形成的物理原因。作答区：________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________21．（13分）质量为0.20kg的小滑块在水平面上压缩轻弹簧后由静止释放。弹簧劲度系数为200N/m，初始压缩量为0.20m。滑块离开弹簧后经过粗糙水平段AB，长度0.50m，动摩擦因数μ＝0.20，随后进入竖直平面内光滑圆轨道，圆轨道半径R＝0.30m。滑块可视为质点，A点处弹簧恢复原长，B点为圆轨道最低点。求：

（1）滑块到达B点时的速度大小；

（2）滑块经过圆轨道最高点时轨道对滑块的弹力大小；

（3）若要使滑块恰好能通过圆轨道最高点，弹簧初始压缩量至少为多少。作答区：________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________22．（13分）某质谱装置可简化为“加速电场+偏转磁场”。带正电的一价离子从静止经电压U＝5.0×10³V加速后，垂直进入磁感应强度B＝0.50T的匀强磁场，在磁场中做半径r＝0.20m的圆周运动。元电荷e＝1.6×10⁻¹⁹C，不计重力。

（1）推导离子质量m与U、B、r、e的关系式，并计算m；

（2）若该离子先经过速度选择器，选择器中电场强度E＝2.0×10⁴N/C、磁感应强度B₀＝0.10T，求能直线通过选择器的离子速度；

（3）要使第（2）问选出的同种离子由静止加速后具有该速度，加速电压应为多大；

（4）从提高质谱仪区分相近质量离子的能力角度，说明增大偏转半径测量精度的意义。作答区：________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

参考答案与解析评分说明：客观题按答案给分；多项选择题全部选对得5分，选对但不全得3分，有错选或不选得0分。计算题中，方法正确但因前一步数值代入错误导致后续结果偏差的，可按相应步骤酌情给后续方法分；单位缺失或有效数字明显不当时，每处最多扣1分。题号题型分值考查重点1单选5v-t图像与位移2单选5平抛运动与速度合成3单选5万有引力与圆周运动4单选5弹性碰撞与动量5单选5电场力做功6单选5安培力7单选5法拉第电磁感应定律8单选5简谐运动能量9多选5理想气体状态变化10多选5闭合电路与串联分压11多选5光电效应规律12多选5驻波与弦振动13填空5光电门测加速度14填空5电容器电荷量与电能15填空5平均感应电动势16填空5热机功与效率17解答10匀变速综合18解答10带电粒子在电场中运动19解答12碰撞实验与误差分析20解答12导体切割磁感线21解答13弹簧、摩擦与圆周运动22解答13质谱仪与速度选择器合计150题号123456789101112答案BCACCBCBACDACBDABD1．答案B。速度—时间图像面积等于位移：加速段位移为(0+12)×4/2＝24m，匀速段位移为12×3＝36m，减速段位移为(12+0)×3/2＝18m，总位移为78m。加速段加速度为3m/s²，减速段平均速度为6m/s，全程平均速率为7.8m/s。2．答案C。竖直方向由静止下落，t＝√(2h/g)＝0.50s，落地时竖直速度vy＝gt＝5.0m/s；水平速度保持5.0m/s，合速度大小为√(5.0²+5.0²)≈7.1m/s。3．答案A。卫星做圆周运动所需向心力由万有引力提供，GMm/r²＝m·4π²r/T²，化简得M＝4π²r³/(GT²)。4．答案C。一维弹性碰撞中，静止小车B的碰后速度vB′＝2mAvA/(mA+mB)＝4.0m/s，因此pB′＝mBvB′＝0.80kg·m/s。5．答案C。电场力做功等于电子动能增加量，大小为eU。电子通过300V电势差，动能增加300eV。板间距影响电场强度，不影响跨越全电压时的能量变化。6．答案B。安培力F＝BILsinθ＝0.40×2.0×0.50×sin30°＝0.20N。7．答案C。磁通量变化率为SΔB/Δt＝2.0×10⁻²×0.60/0.30＝0.040Wb/s，单匝线圈的感应电动势为0.040V，感应电流I＝ε/R＝0.10A。8．答案B。简谐运动角频率ω＝√(k/m)＝10rad/s，通过平衡位置时速度最大，vmax＝ωA＝10×0.10＝1.0m/s。9．答案ACD。等容加热时体积不变，气体对外做功为0；温度升高，理想气体内能增大，压强增大，分子平均动能增大，器壁受到的平均作用效果增强。10．答案AC。串联电路中R₂增大，总电阻增大，总电流I＝E/(R₁+R₂)减小；理想电源输出总功率P＝EI随I减小而减小。R₁两端电压IR₁减小，R₂分得的电压E·R₂/(R₁+R₂)增大。11．答案BD。光电效应中最大初动能由入射光频率决定，与光强无关；光强增大时入射光子数增多，逸出光电子数通常增多。入射光频率增大，最大初动能和遏止电压增大。12．答案ABD。两端固定弦的驻波相邻波节间距离为λ/2，基频f₁＝v/(2L)，允许频率fn＝nf₁。驻波中相邻波腹两侧的质点可能反相振动，因此同时经过平衡位置时速度方向不一定相同。填空题答案与解析13．答案：0.65。解析：两光电门处瞬时速度近似为v1＝0.020/0.040＝0.50m/s，v2＝0.020/0.025＝0.80m/s。由v2²−v1²＝2ax，得a＝(0.80²−0.50²)/(2×0.30)＝0.65m/s²。14．答案：4.0×10⁻³；0.40。解析：Q＝CU＝20×10⁻⁶×200＝4.0×10⁻³C；电容器储能E＝CU²/2＝0.40J。15．答案：1.5；0.30。解析：平均感应电动势大小ε＝N|ΔΦ|/Δt＝100×3.0×10⁻⁴/0.020＝1.5V；平均感应电流I＝ε/R＝1.5/5.0＝0.30A。16．答案：300；37.5%。解析：热机每循环对外做功W＝Q吸−Q放＝800−500＝300J；效率η＝W/Q吸＝300/800＝0.375＝37.5%。解答题答案详解与评分标准17．答案详解：加速段位移x1＝(0+16)×8.0/2＝64m；匀速段位移x