An Axial flow fan has to supply air to an office block. The 18-blade stator is located upstream from the rotor and deflects the air 30 degrees as to allow for corrected flow through the rotor. The air stream has a velocity 35 m/s, the rotor rotates at 2000rpm and the air stream leaves the rotor axially. At a radius of 0.6m calculate: 5.1. The leading edge angle of the rotor. 5.2. The trailing edge angle of the rotor. 5.3 How many blades should there be on the rotor