A space station sounds an alert signal at time intervals of 1. 00 h. Spaceships A and B pass the station, both moving at \(0.400 c_{0}\) relative to the station but in opposite directions. How long is the time interval between signals

(a) according to an observer on \(\mathrm{A}\) and 

\((b)\) according to an observer on B?

(c) At what speed must A move relative to the station in order to measure a time interval of \(2.00 \mathrm{~h}\) between signals?