Answer:
of the velocity of a full size plane in the air
I think it’s the third one idk tho
It depends who is watching it.
-- A passenger on the train says that his clock is normal, but the clock at the station he just passed is running slow.
-- A ticket agent at the station says that his clock is normal, but the clock on the train that just rolled through is running slow.
-- They're both correct, but ...
-- The difference is too small for either of them to notice, unless the train is going faster than about half the speed of light.
-- It isn't.
