本题目来源于试卷: Nuclear & Quantum Physics E.3 Radioactive Decay，类别为 IB物理学
[单选题]
A stationary nucleus of urani5,yx6kly ng/o+* yxy:vz . punum-238 undergoes alpha decp4nqmy, ey2 .hay to form thorium-234. The initial speed of the alpha particle is v. What is correct about the magnitude of .py qmh,ye2n 4the thorium-234 velocity and its direction?
A. Magnitude is $\frac{4}{238}\,v$ ; Direction is Same as the alpha particle
B. Magnitude is $\frac{234}{238}\,v$ ; Direction is Opposite to the alpha particle
C. Magnitude is $\frac{234}{238}\,v$ ; Direction is Same as the alpha particle
D. Magnitude is $\frac{4}{238}\,v$ ; Direction is Opposite to the alpha particle
参考答案: D
本题详细解析:
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