What frequencies will a 1.90 m long tube produce in the audible range (20 hz - 20,000 hz) at 18.0°c for the following cases? (a) the tube is closed at one end lowest frequency hz second lowest frequency hz highest frequency (rounded to the nearest hz) hz (b) the tube is open at both ends lowest frequency hz second lowest frequency hz highest frequency (rounded to the nearest hz) hz

4r-134a enters the condenser of a residential heat pump at 800 kpa and 50°c at a rate of 0.022 kg/s and leaves at 750 kpa subcooled by 3°c. the refrigerant enters the compressor at 200 kpa superheated by 4°c determine (a) the isentropic efficiency of the compressor, (b) the rate of heat supplied to the heated room, and (c) the cop of the heat pump. also, determine (d) the cop and rate of heat supplied to the heated room if this heat pump operated on the ideal vapor-compression cycle between the pressure limits of 200 and 800 kpa. (0.757, 4.37 kw, 5.12, 6.18, 3.91 kw)