Answer:
It is longer
Explanation:
According to the theory of special relativity, moving clocks run slower. So, the construction worker moving at a constant speed observers a time much longer than the time I observe since I am stationary. If t is the time observed by me and v is the speed of the construction worker, then, the time observed by the construction worker, t' is given by
t' = t/√[1 - (v/c)²] where c = speed of light
So, the construction worker reports a longer time interval than me since his time runs slower.
Answer: 4 hours
Explanation: Their approach rate is 100+140 or 240 km/h and 960/240 which equals 4 hours