The highest-energy cosmic-ray particle that had been recorded at the time this text was written was measured by the Fly's Eye HiRes experiment in the Utah desert in 1991. The energy of the particle was 3×1020 eV.
(a) Convert the energy of the particle to joules.
(b) If the particle was a baseball of mass 0.143 kg, calculate the speed of the ball.
(c) Convert your answer to miles per hour and compare your answer to the speed of a fast ball of the fastest major league pitchers (approximately 100 mph, or 45 m s−1).