A metal cube with a rest mass of 2 kg moves at a speed of in frame . What is its total relativistic energy in frame ? Give your answer to 3 significant figures.
A spaceship moves at a speed in frame . Its mass in frame is measured to be 20,000 metric tons. What is its total relativistic energy?
The graph shows the total relativistic energy, , of an object against its speed, . The speed of light, , is defined to be 1. What is the rest mass of the object?