One difference between an actuator disk and a real rotor is that the aerodynamically active parts of real rotor blades do not extend all the way to the rotational axis -the so-called root cut-out. This is because of the need to attach the blades to the hub and also provide flap and lead-lag hinges, as well as a feathering (pitch) bearing. For a root cut-out of 25% of radius and a tip-loss factor B 0.97, estimate the S d additional effect ofthe root cut-out on the induced power factor of a hovering rotor.

Afoot bridge is made as a simple deck, 4 m long, with a cross section 2 m (wide) and 20 cm thick, and made of wood. the deck is supported at the two ends. the maximum load allowable on the bridge is 10 tons, provided it is uniformly distributed on the deck. to sense this load, a strain gauge is placed at the center of the bridge and its resistance is monitored. if the sensor has a nominal resistance of 350 s2 and a gauge factor of 3.6, what is the reading of the strain gauge at maximum load? the modulus of elasticity for the wood used in the construction is 10 gpa.