How do you figure out how fast an aircraft can travel, in Km/H ,if given the weight and the thrust. For example: the aircraft weighs 3,100 lbs and has 20,000lbs of thrust i thought it was 20,000/3,100= 6.5m/s/s which would be 23km/h ? but a 747 weighs around 850,00 lbs and has 124,000lbs of thrust, but is able to cruise at 910km/h. So how do you do it? thanks guys.