A Boxcar Without a Front or a Back Is Moving

Multiple Choice

A boxcar without a front or a back is moving toward the right.Two flashes of light move through the boxcar,one moving from back to front toward the right,the other moving from front to back toward the left.A passenger in the boxcar records how long it takes each flash of light to pass from one end of the boxcar to the other end.According to the passenger,which took longer?

A) the flash going from back to front
B) the flash going from front to back
C) They both took the same time.
D) It depends on whether the passenger is sitting at the front or the back of the boxcar.