Mort is on Earth, and Velma passes him at a high speed. Mort and Velma each carry a standard kilogram. Concerning the kilograms, Velma observes that
A) Velma's is less massive than 1 kilogram and Mort's has a mass of 1 kilogram.
B) Velma's has a mass of 1 kilogram, but Mort's is more massive than 1 kilogram.
C) Velma's has a mass of 1 kilogram, but Mort's is less massive than 1 kilogram.
D) Velma's is more massive than 1 kilogram and Mort's has a mass of 1 kilogram.
E) both have a mass of 1 kilogram.

Question

Quizplus · Accepted Answer

According to the theory of relativity, Velma, moving at high speed, would observe Mort's kilogram as more massive due to relativistic effects, while her own kilogram remains 1 kilogram in her frame of reference.

Mort Is on Earth, and Velma Passes Him at a High