It is desired to flash-mix some chemicals with incoming wastewater that is to be treated. Mixing is to be accomplished using a flat-paddle mixer 500 mm in diameter having six blades. If the temperature of the incoming water is 10°C and the mixing chamber power number is 1.70, determine, (a) the speed of rotation when the Reynolds number is approximately 100,000, (b) why it is desirable to have a high Reynolds number in most mixing operations, (c) the required mixer motor size, assuming an efficiency factor of 20 percent.