Nuclear Physics And Radioactivity Question 87
Question: Rest mass energy of an electron is 0.54 MeV. If velocity of the electron is 0.8 c, then K.E. of the electron is
Options:
A) 0.36 MeV
B) 0.41 MeV
C) 0.48 MeV
D) 1.32 MeV
Show Answer
Answer:
Correct Answer: A
Solution:
$ m_{0}c^{2}=0.54,MeV $ and K.E. = $ mc^{2}-m_{0}c^{2} $ Also $ m=\frac{m_{0}}{\sqrt{1-\frac{v^{2}}{c^{2}}}}=\frac{m_{0}}{\sqrt{1-{{(0.8)}^{2}}}}=\frac{m_{0}}{0.6} $ \ $ E=mc^{2}=\frac{m_{0}}{0.6}c^{2}=\frac{m_{0}c}{0.6}=\frac{0.5,H}{0.6}=0.9,MeV $ \ K.E.= (0.9 ? 0.54) = 0.36 MeV.
BETA
