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rcgldr
#8
Jul16-09, 02:52 AM
HW Helper
P: 7,109
Quote Quote by Brendon_agius View Post
A low friction puck with an airfoil on top, frictionless plane.
The instant the puck is sliding on the plane it is losing kinetic energy, transfer its kinetic energy to the air. Assuming some type of control system that maintains the angle of attack, the path of the puck is a decreasing radius spiral. The greater the lift, the tighter the radius. The lower the drag, the lower the deceleration in speed and radius of the spiral. The momentum changes direction, but decreases in value along with the speed depending on the drag.

While the puck is being accelerated inwards (lift) and backwards (drag), the air affected by the puck is being accelerated outwards and forwards, the Newton third law pair of forces. This interaction is how the kinetic energy is transferred from the puck to the air.