How fast should a moving clock travel if it is to be observed by a stationary observer as running at one-half its normal rate?
A)0.25c
B)0.50c
C)0.65c
D)0.78c
E)0.87c

Question

Quizplus · Accepted Answer

According to the theory of relativity, time dilation is given by the formula $ t' = t/\sqrt{1-v^2/c^2} $. For the clock to run at half its normal rate, $ \sqrt{1-v^2/c^2} = 1/2 $. Solving for $ v $, we find $ v = 0.87c $.

How Fast Should a Moving Clock Travel If It Is