• Question: How fast does an object have to be in order to fly?

    Asked by anon-267549 on 11 Nov 2020.
    • Photo: Sam Geen

      Sam Geen answered on 11 Nov 2020:

      It really depends on the object! Things like the design of the wings, the weight, etc. Think of a small bird like a sparrow taking off (https://www.youtube.com/watch?v=ldM1q6FPb7g) versus a swan that needs a long distance to take off (https://www.youtube.com/watch?v=GdlC-eEk3Lk).

      Apparently planes have different “V-speeds” which tell you how safe it is to take off: https://en.wikipedia.org/wiki/V_speeds

      V1 is the minimum you need to actually take off without crashing at the end of the runway. V2 is the safer speed where you can keep going. VR is when the pilot can start steering the plane to begin the flight properly.

      A 747 takes off at around 184 mph, but the much smaller Cessna plane takes off at under half that. And of course a VTOL or jumpjet like the Harrier can take off without moving forwards at all.

    • Photo: Joshua McAteer

      Joshua McAteer answered on 11 Nov 2020:

      Objects can fly at any speed. Helicopter, quadcopters and hummingbirds can hover. i.e. they can fly with no forward speed at all.

      To fly, you need to produce as much lift as you have gravitational attraction to the Earth. But you can achieve this in any way.

    • Photo: Jesse Dykes

      Jesse Dykes answered on 11 Nov 2020:

      Talking in terms of spaceships, in order to fly, you need to be fast enough to go all the way around the world before you hit the ground. Objects in Low Earth Orbit such as the ISS need to go at about 8 km per second in order to not hit the ground, and remain in orbit

Comments