本题目来源于试卷: Physics Bowl by Topic 4: Kinematics - part III Projectile Motion，类别为 美国物理杯赛(Physics Bowl)
[单选题]
00.36: A ball is thrown vertically upwarpunbnm h+* v8fk;)czk. o c19qmv;wf.6hj,4 cztm8pc6( f b kyd with an initial velocity v and an initial kinetic4jt.h(;pf 6cybc6kv ,mm8 fzw energy $E_k$. When the ball is half way to the top of its flight, what is its velocity and its kinetic energy respectively?
A. $\frac{v}{2} ,\;\;\; \frac{E_k}{2}$
B. $\frac{v}{\sqrt{2}} ,\;\;\; \frac{E_k}{2}$
C. $\frac{v}{4} ,\;\;\; \frac{E_k}{2}$
D. $\frac{v}{2} ,\;\;\; \frac{E_k}{\sqrt{2}}$
E. $\frac{v}{\sqrt{2}} ,\;\;\; \frac{E_k}{\sqrt{2}}$
参考答案: B
本题详细解析:
暂无
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