11. 2 LAWS
NEWTONS BERNOULLI
For every action there is an As the speed of a fluid increases, the
equal and opposite reaction. pressure in the fluid decreases.
Kites excert a downward force upon the air. Air As air passes below the wing it also passes above the
passes over the top edge of the kite and goes wing. The air on top of the wing moves a longer distance
down the upper surface of the kite. As the kite over the curved surface of the wing and moves at a faster
pushes downward on the relatively heavy air it speed. This reduces the pressure above the wing. The air
gets an equal push upwards. This causes the below the wing moves slower than the air above the
kite to have an upward counterforce and to fly. wing. This causes the air pressure to be increased. This
difference in pressure above and below the wing causes a
kite to fly or lift.
12. 3 MAIN FORCES
LIFT
Like an airplane, a kite is heavier than air and relies on the motion of the wind past the kite to generate the
aerodynamic lift necessary to overcome the weight of the kite.
DRAG
The movement of the air is generating an aerodynamic drag
which is overcome by constraining the kite with a control line.
GRAVITY
The aerodynamic lift is overcoming the weight of the kite and the person hanging.
(both a downward force)
15. UPDRAFTS AND TERMALS
A kite also gets higher by updrafts and thermals. Updrafts are formed when the wind rises over the kite's
surface. Thermals are rising bubbles of hot air.
