A relativistic space probe of rest mass m0m_0m0 is propelled by an experimental ion drive. During a deep-space test, the telemetry indicates that the kinetic energy of the probe has reached exactly three times its rest energy.
Calculate the speed of the probe at this point, giving your answer to 3 significant figures.
(Speed of light in a vacuum, c=3.00×108 m s−1c = 3.00 \times 10^8 \text{ m s}^{-1}c=3.00×108 m s−1)