广西柳州市2021届高三下学期第三次模拟考试理科综合试题（PDF版，含答案）

柳州市 2021届高三第三次模拟考试 物理参考答案 二、选择题：本大题共 8小题，每小题 6分。在每小题给出的四个选项中，第 14~18题只 有一项是符合题目要求，第 19~21题有多项符合题目要求。全部选对的得 6分，选对但不 全的得 3分。有选错的得 0分。 题号 14 15 16 17 18 19 20 21 答案 C D B A B BD AD BCD 三、非选择题： 22．（6分）（每空 2分）（1）a/t，0.645 (2)（1-k/2g）tanθ 23．（9分）（第 1空 1分，其余各空每空 2分） （1）Ig/2；DBCA；R2；（2）6.0；（3）7.6 24. (12分) （1）地球表面： g地=G M 地 R 地 2 ·······················································································（1分） 月球表面： g月=G M 月 R 月 2 ·······················································································（1分） g 月= 5 3 ··························································································（2分） （2）竖直上升阶段，由动能定理： （F-mg）h＝mv2/2··········································································（2分） v＝250m/s··················································································· （2分） （3）上升器进入到环月轨道 mg 月＝mv2/r 环················································································ （2分） r 环=1944 km·················································································· （2分） 25．（20分） （1）带电粒子在电场做类平抛运动 L=v0t····························································································（1分） 2 2 1 = 2 at L ······················································································（1分） md qUa 3  ······················································································（1分） m dqB =U 22 ···················································································（1分） （2）粒子射出电场时 vy=at····························································································（1分） 22 0 2 += yvvv ··················································································（1分） r mBq 2vv  ··················································································（1分） 由几何关系知，粒子在磁场中运动的弧长 s为： s=2πr/4·························································································（1分） s=vt′·····································································