2024~2025学年第二学期高二年级期中学业诊断
物理参考答案及评分建议
一、单项选择题:本题包含 7小题,每小题 4分,共 28分。
题号 1 2 3 4 5 6 7
选项 A B B D C D B
二、多项选择题:本题包含 3小题,每小题 6分,共 18分。
题号 8 9 10
选项 AC BD ABD
三、实验题:共 16分。
11.(7分)
(1)不会 (2分) 右 (3分) (2)向左 (2分)
12.(9分)
(1)1.26 (3分) (2) (3分) (3)AB(3分)
四、计算题:共 38分。
13.(8分)
(1)M、N在 1s内各完成一次全振动
周期 T = 1s ················································································· (1分)
从图中可知
波长 = 0.4m··············································································(1分)
可得波速 v = = 0.4m/s·································································(1分)
机械波传播一个半波长,二者分开
t = = 1.5s················································································ (1分)
1
(2)O为振动加强点····································································(1分)
振幅 A=0.2m················································································(1分)
2.5s内 O只完成一次全振动····························································(1分)
S = 4A =0.8m················································································(1分)
14.(14分)
(1)当 v = 0时,由牛顿第二定律得
················································································ (2分)
当 v = v0时,加速度 a = 0,此时导体棒受力平衡
········································································(2分)
·············································································· (2分)
(2)依题意,由能量守恒
··························································(2分)
R与 r串联,电流相同
···················································································· (2分)
·················································································· (2分)
··························································· (2分)
15.(16分)
(1)导体棒减速上滑,电容器放电,
电流的方向为由 N到M···············································································(1分)
导体棒沿斜面向下加速,电容器充电,根据右手定则,
电流的方向为由 N到M···············································································(1分)
(2)撤去外力后,对MN应用动量定理,以沿斜面向上为正方向
2
············································· (2分)
当导体棒到达最高位置,电容器放电完毕
初始时 ········································································· (1分)
电荷量全部放出 ····························································· (1分)
······································································ (1分)
······································································(1分)
(3)依题意,所有电阻不计,电容器两端电压与导体棒两端电势差时刻相等
·······················································································(1分)
·································································(1分)
······························································ (2分)
········································································ (1分)
导体棒在斜面轨道上做匀变速直线运动
·······················································(1分)
····································································· (1分)
··············································(1分)
3