As measured in Earth's rest frame, a spaceship traveling at 0.9640c takes $10.5 \mathrm { y }$ to travel between two planets that are not moving relative to each other. How long does the trip take as measured by someone on the spaceship?
A)2.79 y
B)6.83 y
C)39.5 y
D)28.8 y

Question

Quizplus · Accepted Answer

The time dilation formula is $ t' = t \sqrt{1 - v^2/c^2} $. Plugging in $ t = 10.5 $ y and $ v = 0.9640c $, we get $ t' = 10.5 \sqrt{1 - (0.9640)^2} \approx 2.79 $ y.

As Measured in Earth's Rest Frame, a Spaceship Traveling at 0.9640c