At the design conditions, the velocity triangle at the mean radius of a single-stage axial compressor is such that the blade angle at the rotor exit is equal to 30°. The absolute velocities at the rotor inlet and exit are equal to 140 m/s and 240 m/s, respectively. The flow velocities relative to the rotor at the inlet and exit of the rotor are equal to 240 m/s and 140 m/s, respectively. The blade speed (U) at the mean radius of the rotor is _______ m/s. (round off to two decimal places)