Quote (ChivasRegal @ May 26 2017 08:31pm)
that doesn't make any sense at all...
how does a helium balloon float up into the sky if gravity is pulling it to the ground?
how do hang gliders leap off a cliff and fly straight out? shouldn't gravity just pull them straight down to bottom of cliff?
gravity is automatically dipping the nose of every single aeroplane in the world, every second it is in the air? you truly believe this????
Balloon floats because gravity is pulling on the air harder than it's pulling on the balloon. The same reason why a person on one end of a seesaw will rise if a heavier person sits on the other end. A balloon full helium is lighter than an equivalent volume of air, so the air takes its place and pushes it up.
Gravity does pull hang gliders down, but they are designed to maximize air resistance and create lift while moving, so they fall very very slowly. Hopefully you believe in air resistance, since it's easily shown even with lateral movements that have nothing to do with gravity.
Well, gravity is pulling every airplane down. Whether it's tipping the nose depends on the center of gravity and where other forces are applied to the airplane.
This post was edited by russian on May 26 2017 10:39pm