Acquisition cost. Refers to the price (including the closing costs) to purchase another company or property. In the context of investments, refers to price plus brokerage commissions, of a security, or the sales charge applied to load funds.
The pressure imbalance that produces lift creates a problem at the wing tips. The higher-pressure air below a wing spills up over the wing tip into the area of lower-pressure air above. The wingâs forward motion spins this upward spill of air into a long spiral, like a small tornado, that trails off the wing tip. These wing tip vortices create a form of pressure drag called vortex drag. Vortices reduce the air pressure along the entire rear edge of the wing, which increases the pressure drag on the airplane. The energy required to produce a vortex comes at the expense of the forward motion of the airplane. Tilting the airplaneâs wings upward makes the vortices stronger and increases vortex drag. Vortices are especially strong during takeoff and landing, when an airplane is flying slowly with its wings tilted upward.
Extending flaps or slats increases the wing camber (curvature), the CL and the geometric AOA both reduce. The lift formula tells us that if CL increases IAS must decrease if lift is to remain constant. So therefore stall speed and AOA both are reduced. Lowering the flaps also increases drag, especially when beyond 25Â°.