A-3.25 consider a naca 2415 airfoil section in a low-speed wind tunnel. assume re 9 x 106 a) what is the zero-lift angle of attack? b) does this airfoil have negative or positive camber? c) what is the stalling angle of attack? d) what is the maximum value of ci? e) what is the lift-curve slope?

Apulley system is used to lift a 2,000 newton engine up a distance of 3 meters. the operator must apply a force of 250 newtons to the chain of the pulley system to lift the motor. to lift the engine 3 meters, the operator must pull a total of 30 meters of chain through the pulley system. what is the value of di?

Ascientific blank must be testable and capable of being proven false?

What can you increase the strength of an electromagnet by