When at rest, a spacecraft has the same height as length. When moving at relativistic speeds in the direction of its length, which one of the following describes its length and height to an observer at rest?
A) Its length is decreased and its height is increased.
B) Its length is decreased and its height is decreased.
C) Its length is decreased and its height is unchanged.
D) Its length is unchanged and its height is increased.
E) Its length is increased and its height is decreased.

Question

Quizplus · Accepted Answer

Lorentz contraction, a consequence of Einstein's theory of relativity, states that an object moving at relativistic speeds will appear shorter in the direction of motion to a stationary observer, while dimensions perpendicular to the motion (like height) remain unchanged.

When at Rest, a Spacecraft Has the Same Height as Length