阿摩線上測驗
60. A spacecraft is flying towards Earth at a speed of 0.7 c. When it is 8 light-years away from Earth,
it sends a message to Earth at a speed of 0.5 c (relative to the spacecraft). How long will it take
for Earth to receive this message?
(A) 5 years
(B) 6 years
(C) 7 years
(D) 8 years
(E) 9 years
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統計： A(0), B(0), C(1), D(0), E(8) #3233326
統計： A(0), B(0), C(1), D(0), E(8) #3233326
