An object moves in a direction parallel to its length with a velocity that approaches the velocity of light. The width of this object as measured by a stationary observer
A) increases slightly.
B) approaches infinity.
C) approaches "gamma".
D) does not change.
E) approaches zero.

Question

Quizplus · Accepted Answer

According to the theory of relativity, length contraction only occurs in the direction of motion. Since the object is moving parallel to its length, its width, which is perpendicular to the direction of motion, does not change.

An Object Moves in a Direction Parallel to Its Length