A spaceship traveling at constant velocity passes by Earth and later passes by Mars.In which frame of reference is the amount of time separating these two events the proper time?
A)the Earth frame of reference
B)the Mars frame of reference
C)the spaceship frame of reference
D)any inertial frame of reference
E)any frame of reference,inertial or not

Question

Quizplus · Accepted Answer

The proper time is the time interval measured by a clock that is at rest in the same reference frame as the events being compared. In this case, the spaceship is the only clock that is present in both events, so the proper time is measured in the spaceship's frame of reference.

A Spaceship Traveling at Constant Velocity Passes by Earth and Later