GATE Civil Engineering (CE) 2017 Shift 2 Solved Paper

Two cars P and Q are moving in a racing track continuously for two hours. Assume that no other vehicles are using the track during this time. The expressions relating the distance travelled d (in km) and time t (in hour) for both the vehicles are given as
P (d) = 60t
Q (d) = 60t²
Within the first one hour, the maximum space headway would be