Reference frame S' passes reference frame S with a certain velocity. Events 1 and 2 are to have a certain temporal separation At' according to the S' observer. However, their spatial separation Ax' according to that observer has not been set yet. The figure below gives their temporal separation At according to the S observer as a function of Ax' for a range of Ax' values. The vertical axis scale is set by At = 9.00 us. What is At' in case Ax'=0? Al K 200 A (m) Ar (ps) 400

Reference frame S' passes reference frame S with a certain velocity. Events 1 and 2 are to have a certain temporal separation At' according to the S' observer. However, their spatial separation Ax' according to that observer has not been set yet. The figure below gives their temporal separation At according to the S observer as a function of Ax' for a range of Ax' values. The vertical axis scale is set by At = 9.00 us. What is At' in case Ax'=0? Al K 200 A (m) Ar (ps) 400