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tobywashere
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Homework Statement
The positron and the electron each have a rest mass of 9.11 x 10-31 kg. In a certain experiment, an electron and a positron collide and vanish, leaving only electromagnetic radiation after the interaction. Each particle is moving at a speed of 0.20c relative to the laboratory before the collision. Determine the energy of the electromagnetic radiation.
Homework Equations
Total energy of a particle:
The Attempt at a Solution
Using the equation:
(9.11 x 10-31)c2 / sqrt[1 - (0.2c)2/c2]
= 8.37 x 10-14 J
This is the total energy of one electron or positron. Since two particles are colliding, the total energy of the system is 8.37x10-14 x 2 = 1.67 x 10-13 J
When the particles vanish, all the energy is converted to electromagnetic radiation, so the energy of the electromagnetic radiation is 1.67 x 10-13 J
However, the answer in my textbook says 0.615 MeV, which is 9.84 x 10-14 J. My textbook is known to have mistakes, so I am checking if this is my mistake or the textbook's mistake.
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