the flapping of the wings propel the bird forwards
A plane flies forwards by exerting a force on the air with its wings. the air pushes back on those wings with an equal force that propels the bird forwards
A compressed C02 tank or High Pressure Air tank propels the paintball.
The propeller.
It propels.
Air
Propels it (moves it)
A jet engine usually propels an airplane. The jet engine propels the plane by ejecting extremely hot gasses out the back of the engines. Another way is by using huge fans to suck in air and blow it out the back.
Pseudostratified ciliated columnar epithelial tissue propels substances across surfaces.
It propels it forward in the water.
energy
energy
The engines propel the airplanes.