Superman, who has exceptionally strong arm, throws a fast ball with a speed of 0.9c. If the rest mass of the ball is 0.5 kg, what is its mass in flight?
The ball goes with relativistic speed and according to the results of Einstein’s Special Theory of Relativity (Einstein, see in Pashto), its mass will increase.
Let its relativistic mass is m, then
Now put the given values of v = 0.9c and m0 = 0.5 kg, we have,
So the increase is more than the double of the rest mass.