2026届北京海淀区九年级物理中考三模模拟试卷（含答案详解与评分标准）第021套

2026届北京海淀区九年级物理中考三模模拟试卷（含答案详解与评分标准）第021套学校：________________班级：________________姓名：________________考号：________________考试时间：120分钟满分：120分注意事项1．本试卷分为选择题、填空题和解答题三部分，共26题。请在规定位置作答，保持卷面整洁。2．选择题每题只有一个选项符合题意；填空题只填写必要结果和单位；解答题应写出主要依据、必要步骤和结果。3．本卷计算中取g＝10N/kg，水的密度取1.0×10³kg/m³，水的比热容取4.2×10³J/(kg·℃)。4．本卷面向中考三模综合检测，重点考查阶段复习中的基础概念、实验能力、计算能力和综合应用能力。一、选择题（共12题，每题3分，共36分）1．下列估测最接近实际的是（）A．一个鸡蛋的质量约5kgB．一节新干电池电压约1.5VC．中学生百米跑平均速度约30m/sD．北京春季室外气温约70℃2．关于声现象，下列说法正确的是（）A．只要物体振动，人耳一定能听到声音B．声音在真空中传播速度最大C．“禁止鸣笛”是在声源处减弱噪声D．音调高低主要由振幅决定3．把正在熔化的冰放在0℃房间中，冰水混合物的温度保持0℃较长时间。下列说法正确的是（）A．晶体熔化时吸热但温度不变B．非晶体熔化时温度一定不变C．冰熔化过程中不吸收热量D．水凝固时温度一定升高4．下列关于光现象的说法正确的是（）A．小孔成像由光的反射形成B．平面镜所成的像能用光屏承接C．近视眼应佩戴凸透镜进行矫正D．凸透镜对通过它的光有会聚作用5．在水平路面上匀速行驶的校车突然刹车，乘客身体会向前倾。下列解释正确的是（）A．乘客受到向前的推力B．乘客的惯性突然增大C．乘客上身由于惯性保持原来的运动状态D．刹车后乘客不再受到重力6．下列关于简单机械的说法正确的是（）A．使用定滑轮可以改变力的方向B．省力杠杆一定省功C．动滑轮既能省力又能省功D．斜面越光滑机械效率越低7．两个规格不同的小灯泡串联接入电路，闭合开关后都发光。下列判断正确的是（）A．两灯两端电压一定相等B．通过较亮灯泡的电流较大C．通过两灯泡的电流相等D．两灯电阻一定相等8．关于家庭电路与安全用电，下列做法正确的是（）A．用湿手拨动开关B．保险丝熔断后用铜丝替代C．开关接在零线和用电器之间D．带金属外壳的用电器使用三孔插座9．下列设备与其工作原理对应正确的是（）A．验电器——同种电荷相互吸引B．电动机——通电导体在磁场中受力C．发电机——电流的磁效应D．电磁继电器——电磁感应10．一块金属的质量为54g，体积为20cm³。结合常见物质密度表判断，该金属最可能是（）A．铜，8.9g/cm³B．铁，7.9g/cm³C．铝，2.7g/cm³D．水银，13.6g/cm³11．某定值电阻两端电压从2V增至6V时，通过它的电流由0.2A增至0.6A。下列说法正确的是（）A．电阻随电压增大而增大B．该电阻的阻值为10ΩC．电流与电压成反比D．电压为0时电阻为012．甲、乙两电热器分别标有“220V100W”和“220V40W”，都在额定电压下正常工作。下列说法正确的是（）A．相同时间内甲产生的热量多B．乙的电阻较小C．通过甲的电流较小D．甲、乙消耗相同电能二、填空题（共6题，每题3分，共18分）13．在一次体育测试中，小明沿直线跑完600m用时75s，他全程的平均速度为________m/s；到达终点后不能立即停下，是因为人具有________。答：____________________________________________________________________14．光从空气斜射入水中时传播方向发生改变，这种现象叫光的________；此时折射角通常________入射角。答：____________________________________________________________________15．某透明水槽中水深0.40m，水对槽底的压强为________Pa；若槽底受水面积为0.020m²，水对槽底的压力为________N。答：____________________________________________________________________16．质量为0.20kg的铜块温度升高50℃，吸收的热量为________J（c铜＝0.39×10³J/(kg·℃)）；升温过程中铜块的内能________。答：____________________________________________________________________17．一只小灯泡正常发光时两端电压为6V，通过电流为0.5A，则它正常发光时的电阻为________Ω，电功率为________W。答：____________________________________________________________________18．焦距为10cm的凸透镜前放一支点燃的蜡烛，蜡烛到透镜的距离为30cm，此时光屏上能成________、________的实像。答：____________________________________________________________________三、解答题（共8题，共66分）19．（6分）某小组用斜面、小车、刻度尺和秒表测量小车的平均速度。斜面上端A到下端C的距离为1.20m，中点为B。小车从A由静止释放，记录到达B、C的时间如下表。路段路程/m所用时间/s平均速度/(m·s⁻¹)A到B0.602.0B到C0.601.0A到C1.203.0（1）完成表格中空缺的平均速度。（2）根据数据判断小车沿斜面下滑过程中速度如何变化，并说明判断依据。（3）若小车过了B点后才按下秒表记录B到C的时间，则测得B到C的平均速度偏大还是偏小？说明理由。________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________20．（7分）阅读材料，回答问题。材料：海淀区某学校组织中考三模适应性演练时，老师强调乘坐校车必须系好安全带。校车座椅安全带较宽，雨天上车前台阶处铺有防滑垫，车辆行驶中驾驶员保持平稳加速和减速。（1）从惯性的角度解释车辆突然刹车时乘客身体为什么容易向前倾。（2）安全带做得较宽，在约束乘客身体时有什么物理好处？（3）防滑垫能增大摩擦的主要原因是什么？在雨天它对安全有什么作用？________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________21．（7分）小华用焦距为10cm的凸透镜探究成像规律，调节蜡烛、凸透镜和光屏，使三者中心大致在同一高度。部分实验数据如下。实验序号物距u/cm像距v/cm像的大小像的倒正像的虚实13015缩小倒立实像22020等大倒立实像31530（1）补全实验序号3中像的性质。（2）实验序号1的成像特点与生活中的哪种光学仪器相同？（3）实验中为什么要调节三者中心大致在同一高度？若用手遮住透镜上半部分，光屏上像的变化情况如何？________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________22．（8分）某实验小组用电压表和电流表测量未知电阻Rx的阻值，实验电路连接正确，电源电压可调。测得数据如下表。次数1234U/V1.01.52.02.5I/A0.100.150.200.25Rx/Ω（1）把表格最后一行补充完整，并求Rx的平均值。（2）根据表中数据说明通过Rx的电流与其两端电压的关系。（3）若某次实验电流表选用0～0.6A量程，指针位于0.18A处读成0.9A，将会怎样影响该次计算出的电阻？________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________23．（8分）某班进行电热水壶综合复习实验。壶内装有1.5kg的水，初温为20℃，正常工作10min后水温升至80℃。电热水壶额定功率为800W，不计水壶外壳吸热但考虑向环境散热。求：（1）水吸收的热量。（2）电热水壶10min消耗的电能。（3）本次加热过程中电热水壶的加热效率。________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________24．（10分）一个底面积为0.010m²、高为0.20m、质量为2.0kg的实心长方体物块静止放在水平桌面上。将它缓慢放入水中时，物块能够完全浸没，且不吸水。求：（1）物块静止在水平桌面上时对桌面的压强。（2）物块完全浸没在水中时受到的浮力。（3）若用细线竖直向上拉住物块，使其在水中恰好有一半体积露出水面并保持静止，细线对物块的拉力大小。________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________25．（12分）如图示意的串联电路中，电源电压恒为12V，定值电阻R1＝20Ω，滑动变阻器R2标有“50Ω1A”。闭合开关后，电压表测R1两端电压，电流表测电路电流。某时刻电压表示数为4V。求：电路示意：电源、开关、R1、R2依次串联；电压表并联在R1两端；电流表串联在电路中。（1）此时通过R1的电流和R2接入电路的阻值。（2）在保证电路安全且滑动变阻器允许范围内，R1消耗电功率的最大值和最小值。（3）当R2接入电路的阻值为10Ω时，通电10s，R2产生的热量。________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________26．（8分）综合实践题。材料：为迎接中考三模后的科技节，某校九年级同学设计了一辆太阳能小车。太阳能板在稳定光照下输出电压为6V、输出电流为0.25A。小车在水平地面上匀速直线前进，速度为0.50m/s，受到的水平牵引力为0.60N。小车连续运行10min。（1）太阳能板的输出功率是多少？（2）10min内太阳能板输出的电能是多少？（3）这段时间小车克服阻力做的机械功是多少？机械效率是多少？（4）从能量转化或运动阻力角度提出一条提高太阳能小车效率的合理措施。________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

参考答案与解析一、选择题答案与关键理由题号123456789101112答案BCADCACDBCBA1．答案：B。解析：常用新干电池电压约为1.5V；一个鸡蛋质量约50g，中学生百米平均速度约7m/s，北京春季气温不可能接近70℃。2．答案：C。解析：“禁止鸣笛”控制发声，属于在声源处减弱噪声；声音传播需要介质，真空不能传声；音调由频率决定。3．答案：A。解析：冰是晶体，熔化过程中持续吸热，但温度保持在熔点0℃附近不变。4．答案：D。解析：凸透镜对光有会聚作用；小孔成像是光沿直线传播，平面镜成虚像，近视眼应用凹透镜矫正。5．答案：C。解析：刹车时车速减小，乘客下身随车减速，上身由于惯性仍保持原来的运动状态，因此向前倾。6．答案：A。解析：定滑轮本质上是等臂杠杆，不省力，但能改变拉力方向；任何机械都不能省功。7．答案：C。解析：串联电路只有一条电流路径，各处电流相等；不同灯泡电阻不同，分得的电压和亮度可以不同。8．答案：D。解析：金属外壳用电器接三孔插座可使外壳接地，提高安全性；湿手操作、铜丝替保险丝、开关接零线均不安全。9．答案：B。解析：电动机利用通电导体在磁场中受力转动；发电机主要利用电磁感应，验电器利用同种电荷相互排斥。10．答案：C。解析：密度为54g÷20cm³＝2.7g/cm³，与铝的密度相符。11．答案：B。解析：用任一组数据求得阻值为10Ω，定值电阻阻值不随两端电压变化而改变。12．答案：A。解析：额定电压下甲的功率更大，相同时间消耗的电能和产生的热量更多；甲的电阻较小、电流较大。二、填空题答案与解析13．答案：8；惯性。解析：平均速度为600m÷75s＝8m/s；人到终点后仍有保持原来运动状态的性质，即惯性。14．答案：折射；小于。解析：光从空气斜射入水中，传播方向改变属于折射；由光路特点可知折射角小于入射角。15．答案：4.0×10³；80。解析：水深0.40m时水对底部压强为1.0×10³×10×0.40＝4.0×10³Pa；压力为4.0×10³×0.020＝80N。16．答案：3.9×10³；增大。解析：铜块吸热为0.20×0.39×10³×50＝3.9×10³J；物体温度升高，内能增大。17．答案：12；3。解析：电阻为6÷0.5＝12Ω；电功率为6×0.5＝3W。18．答案：倒立；缩小。解析：物距30cm大于二倍焦距20cm，凸透镜成倒立、缩小的实像。三、解答题答案详解与评分标准19．（6分）答案与评分：（1）A到B平均速度：0.60m÷2.0s＝0.30m/s；B到C平均速度：0.60m÷1.0s＝0.60m/s；A到C平均速度：1.20m÷3.0s＝0.40m/s。（每空1分，共3分）（2）小车沿斜面下滑速度逐渐增大。依据是B到C的平均速度0.60m/s大于A到B的平均速度0.30m/s。（判断1分，依据1分）（3）偏大。过了B点后才开始计时，实际计时起点滞后，会使记录的B到C时间偏小；按相同路程计算平均速度时，时间偏小会导致速度偏大。（结论1分，理由1分）20．（7分）答案与评分：（1）车辆突然刹车时，车和乘客下身受到座椅、地板作用速度迅速减小，乘客上身由于惯性仍要保持原来的向前运动状态，所以身体向前倾。（3分）（2）安全带较宽，在压力一定时增大受力面积，可减小对人体的压强，降低勒伤风险。（2分）（3）防滑垫表面较粗糙，能增大接触面粗糙程度，从而增大摩擦；雨天可减少脚底打滑，提高上下车安全性。（2分）21．（7分）答案与评分：（1）实验序号3中，物距15cm在一倍焦距和二倍焦距之间，像距30cm大于二倍焦距，像为放大、倒立、实像。（3分）（2）实验序号1中物距大于二倍焦距，成倒立、缩小的实像，与照相机成像特点相同。（1分）（3）调节三者中心在同一高度，是为了使像成在光屏中央；遮住透镜上半部分后，仍能成完