100 kg of - is to be cooled from 10 degrees * C to - 20 degrees * C . The diameter of the Spherical liver equals 7cm. Assume that the density of the liver is equal to 1000 kg/m3 , heat transfer coefficient and convection equals to 50 W/m2 . K. (the air temperature equals -30 C.) A. chose one only 1- Using the specific heat, determine the amount of heat that must be removed from the lamb. 2- How much actual heat must be removed during this process? B. Estimate the time required for freezing. ​

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

Along 8-cm diameter steam pipe whose external surface temperature is 900c connects two buildings. the pipe is exposed to ambient air at 70c with a wind speed of 50 km/hr blowing across the pipe. determine the heat loss from the pipe per unit length. (b) air at 500c enters a section of a rectangular duct (15 cm x 20 cm) at an average velocity of 7 m/s. if the walls of the duct are maintained at 100c. a) the length of the tube for an exit temperature of the air to be 40 0c. b)the rate of heat transfer from the air. c) the fan power needed to overcome the pressure drop in this section of the duct.

An open feedwater heater operates at steady state with liquid entering at inlet 1 with t? = 40°c and pl = 1 .2 mpa. water vapor att2-200°c and p2 = 1.2 mpa enters at inlet 2. saturated liquid water exits with a pressure of pa 1.2 mpa. neglect heat transfer with the surroundings and all kinetic and potential energy effects, determine the mass flow rate of steam at inlet 2 if the mass flow rate of liquid water at inlet 1 is given as 2 kg/s.