When two pumps are both operating, the sound pressure level at a distance of 10 m from the pumps is 101.8 dB. When pump A is turned off (only pump B operating), the measured sound pressure level at 10 m from the pumps is 97.0 dB. Determine the sound pres- sure level when pump B is turned off and only pump A is operating. The sound waves are radiated through air at 228C (205.2K or 728F) and 101.3 kPA (14.7 psia).

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.