question_answer 12)

An electron and a proton are detected in a cosmic ray experiment, the first with kinetic energy 10 keV, and the second with 100 keV. Which is faster, the electron or the proton ? Obtain the ratio of their speeds. (Electron mass proton mass .  

Answer:

K.E. of the electron K.E. of the proton               or            or            or            Thus the electron moves faster than the proton.