Two stars are at rest relative to each other. In their common rest frame, these stars are 90.0 light-years apart. If they are measured to be $68.7 \text { light-years }$ apart by the navigator of a spaceship traveling between them, how fast is the spaceship moving relative to these stars?
A)0.646c
B)0.604c
C)0.558c
D)0.505c

Question

Quizplus · Accepted Answer

The length contraction formula is $ L = L_0 \sqrt{1 - v^2/c^2} $, where $ L_0 = 90.0 $ light-years and $ L = 68.7 $ light-years. Solving for $ v $, we find $ v \approx 0.646c $.

Two Stars Are at Rest Relative to Each Other 68.7 light-years 68.7 \text { light-years }68.7 light-years

Two Stars Are at Rest Relative to Each Other $68.7 \text { light-years }$