You are designing an airplane propeller that is to turn at 2400 rpm (Fig. 9.13a). The forward airspeed of the plane is to be 75.0 m/s 75.0 m/s, and the speed of the propeller tips through the air must not exceed 270 m/s 270 m/s. (This is about 80% of the speed of sound in air. If the propeller tips moved faster, they would produce a lot of noise.) What is the maximum possible propeller radius?