Relative to a stationary observer, a moving clock
A) always runs slower than when at rest.
B) can run faster or slower; it depends on the relative velocity between the observer and the clock.
C) always runs faster than when at rest.
D) keeps its normal time.

Question

Quizplus · Accepted Answer

According to the theory of relativity, a moving clock, as observed from a stationary frame of reference, always runs slower than it does when it is at rest. This phenomenon is known as time dilation.

Relative to a Stationary Observer, a Moving Clock