[450knotOffice]

If a wing is very efficient in producing lift, and if the airframe attached to that wing is very light, and if the wing is very large compared to that airframe, then enough lift will be produced to fly at a very, very low airspeed. There are a few very specialized bush planes built that can get airborne with as little as 35 mph of airspeed over the wings. If one of theose airplanes were to be pointed into a 35 to 40 mph wind, it would levitate.

To answer your question, BRPORSCHE, normal liftoff speed for an Embraer is in the vicinity of 130 knots (150 mph or so). Within 15 seconds, however, it has accelerated to 200 knots, and within another minute it's climbing at 250 knots. Five minutes later it's climbing at about 300 knots. By the time it levels off at 37,000 feet 20 minutes later, it's finishing its climb at about 420 knots (true airspeed) and will cruise at about 445 knots or so.