Physics 2






“…Every great advance in science has issued from a new audacity of imagination…”

-         John Dewy



It is the scientific study of how objects move through the air. It also explains what happens when air, or for that matter, any gas moves rapidly. Aerodynamics deals with air moving against a gadget – let us say an airplane moving through air in the sky, or, let us assume, like wind filling the sails of a boat. In both the cases – in airplane and the sailboat, the principle, the law, is the same! Man has developed a craving, an insatiable desire to fly, the culprits being birds! Flying like a bird could only be possible if man had an understanding of aerodynamics. This quest began some 200 years ago! 

Bernoulli’s Principle: 

A Swiss Mathematician – Daniel Bernoulli, was investigating what really happened to water flowing through a pipe when it got blocked. What he discovered was that the water flowed faster as it went past an obstacle. He also found that when water flowed faster, it lost some quantity of its normal pressure. If the speed is slow, the pressure is high, if the speed is great than the pressure is low. 

Giovanni Venturi: Basing the Bernoulli’s principle, but using air instead of water, Venturi developed a tube, called Venturi tube. 

The air pressure dropped at the neck level, though the force increased greatly. You can see a similarity is shape between the wing a airplane and the neck pattern of the venturi tube.



The pressure on the topside of the wing is less, as the wind speed is great. The pressure on the bottom side o f the wing is great as the wind speed is less, resulting in the wing rising above the ground. 


In an airplane you have Aileron, Rudder and Elevators for controlling the right and left banking, for left and right turns and for climbing and diving. 

Rudder Control Position 

 Elevator Control Position 


In a wind yacht, there is no thrust of its own and no lift, but drag is there. What propels is the force of wind.


In a land sailing yacht, the aileron and rudder are in the sail positioning in relation to the direction of the wind. 

The wings of an airplane and the sails of a wind sailing yacht (both on water or on land) can work best only when the air flows very smoothly over them. This is possible only if the shape of the sail is correct together with the angle of air attack in the proper position.