A Cessna aircraft has a liftoff speed of 120 km/h. (a) What minimum constant acceleration does the aircraft require if it is to be airborne after a takeoff run of 250 m? (b) How long does it take the aircraft to become airborne? I tried using an equation for constant acceleration and plugged in: .277^2=0+2a(250). When I solved for a I got .000153 and it was incorrect. any suggestions?