2021届西省宝鸡陕市高三上学期高考模拟检测（一）理科综合试题 PDF版

物理部分参考答案（2021年市一检）

第Ⅰ部分（选择题）

14．B  15．C  16．D  17．C  18．A  19．AD  20．BC   21．ABD

第Ⅱ卷（非选择题）

22．（6分，每空2分） 电流    10     91

23．（9分）

（1）不    减小（2分）

（2）会（2分）

（3）1.8（2分）

（4）a－F图像如右图所示（1分）    0.50（2分）

24．（14分）

解：（1）设小球在C点的速度为，小球从A点运动C点过程中，由动能定理可得：

································································（1）2分

小球在C点时水平方向的支持力与电场力Eq的合力提供向心力，所以有：

································································（2）2分

由牛顿第三定律可得小球对轨道的压力与支持力大小相等，即·················（3）1分

解得：···························································（4）1分

（2）小球过C点上升到达最高点的过程中，由运动的分解可知，在水平方向小球做初速度为零的匀加速运动，竖直方向做竖直上抛运动。设小球从C点到最高点的时间为t，则有：

································································（5）1分

································································（6）1分

································································（7）1分

小球从A点开始运动到达最高点过程中电场力做功为：·······················（8）2分

由电场力做功与电势能变化关系式可得：·································（9）1分

解的：···························································（10）2分

即：小球从A点开始到最高点的过程中，电势能减小了。

25．（18分）

解：（1）设载货卡车在时间内做匀加速运动的位移为，由运动学公式可得：

································································（1）2分

解得：···························································（2）1分

由于＞，所以卡车能在绿灯转黄灯前车尾通过人行横道。·····················2分

（2）设当卡车加速行驶时速度为，位移为，由运动学公式可得：

································································（3）1分

································································（4）1分

设卡车从开始刹车到钢锭撞上车头运动的时间为t'，卡车速度为v2，位移为s2，钢锭位移为s2'，卡车匀减速运动的加速度大小为a1，由运动学公式及它们间的位移关系可得：

································································（5）1分

································································（6）1分

································································（7）1分

································································（8）1分

································································（9）1分

所以可得：·······················································（10）1分

（3）设卡车和钢锭发生完全非弹性碰撞后的共同速度为v3，对碰撞过程由动量守恒定律可得：

································································（11）1分

设卡车和钢锭一起再次做匀减速运动的加速度大小为，位移为，由动力学方程和运动学公式可得：              （12）1分

································································（13）1分

解得：        ····················································（14）1分

由于＜，所以卡车停止运动时车头压上了人行横道线。·······················1分

33．（15分）

（1）（5分）ADE

（2）（10分）

解：①解：活塞缓慢上升过程发生等圧変化，由盖·吕萨克定律可得：

         ····························································（1）2分

································································（2）2分

解得：t2=57°C·····················································（3）1分

②设活塞封闭气体的压强为P，活塞缓慢上升过程中受力平衡，则有：

································································（4）1分

气体体积增大，外界对气体做负功，由做功公式可得：·······················（5）1分

由热力学第一定律可得：·············································（6）2分

解得：···························································（7）1分

34．（15分）

（1）（5分）ABD

（2）（10分）

解：①光在直角三棱镜中传播的光路图如图所示，设光在AD界面的入射角为r，折射角为i ，根据几何知识和折射定律可得：

······································（1）1分

······································（2）1分

······································（3）2分

解得：·································（4）1分

②根据直角三角形的边角关系可得：

······································（5）1分

······································（6）2分

······································（7）1分

解得：·································· （8）1分