Question

Identify which of the following would be a correct assumption to make for a traveller in a spaceship travelling at $0.98c$ according to Einstein's theory of relativity?

• A. Clocks on the spaceship run more slowly
• B. The spaceship will appear shortened
• C. The mass of the spaceship increases while it is in motion
• D. Light travels at the same velocity for the traveler whether he is moving or not moving
• E. All of these assumptions would be correct

Answer 1

The correct option is E All of these assumptions would be correct

Option D is the first postulate of Special Theory of Relativity. It states that the speed of light is constant in all inertial frames. Thus the speed of light would appear to be the same to a moving or stationary person.

The other options are direct results of the postulates of the theory.

Time dilation takes place in relativity, which means that the clocks of other inertial frames(moving) appear to slow down with respect to other observers.

Another effect is length contraction. The length of objects along the direction of velocity appears to have shrunk.

Also the mass of a moving object with respect to an observer appears to have increased, compared to when it was at rest with respect to the observer.