Uniform Motion Related Problem

Two planes leave an airport at 2 p.m., one flying south at 450 kph, the other flying north at 675 kph. At what time will they be 3 600 apart?

1 answer

1. -450 km/h(South).
2. 675 km/h(North).

675T - (-450T) = 3600 km.
Solve for T.