The sound pressure level from a fan is measured to be 65 db at 3 m from the source. it can be assumed that the fan can be treated as a point source for the measurement. estimate the sound power of the fan if it is now placed in a 0.2 m x 0.2 m square duct. also, estimate the sound pressure level in the duct.

Water at 70°f and streams enter the mixing chamber at the same mass flow rate, determine the temperature and the quality of the exiting stream. 0 psia is heated in a chamber by mixing it with saturated water vapor at 20 psia. if both streams enters the mixing chamber at the same mass flow rate, determine the temperature and the quality of the existing system.