Lift
Lift is the upward push that air creates on an object when it moves through the air.
Hold a flat tray level and walk fast through a room. Air pushes up on the bottom more than it pushes down on the top. That pressure gap creates an upward push — lift. The faster you move, the stronger that push gets.
Explaining lift by grade level
When you throw a paper plane, air pushes up under the wings. That push holds the plane up as it flies. The shape of the wings helps catch more air. Without that push, the plane would just fall to the ground.
Projects that explore lift
Point a hair dryer straight up and place a ball in the stream. The upward airflow hits the bottom of the ball and slows down, building higher pressure beneath it. That pressure pushes up against gravity, and the ball stays suspended in midair without anything touching it.
How you fold a paper airplane changes how much upward push the air creates on its wings. A plane with wider wings catches more air beneath them and may glide farther. A narrow design cuts through the air faster but loses that upward push sooner and drops quicker.