text: changes in velocity, pressure, 
  take place 
  density and flow direction will 
  quite suddenly through 
  the various. wave 
  forms. The shape of the object and the 
  required flow ,direction change dictate the 
  type and strength of the wave formed. 
  
  (2) As always, lift results from the distri- 
  bution of pressure on a surface and is the net 
  force perpendicular to the free stream direc- 
  tion. Any component of the lift in a direc- 
  the windstream will be 
  tion parallel 
  drag due to lift. 
  
  to 