Question

If the total energy of a particle is exactly twice its rest energy, then its speed in terms of the speed of light c is

Answer 1

E = Ek + E0 = m c^2

2E0 = m c^2

2 m0 c^2 = m0 c^2 / (1 - (v/c)^2)^1/2

1 - (v/c)^2 = 1/4

v / c = (3 / 4)^1/2