Atruncated solid cone is of circular cross section, and its diameter is related to the axial coordinate by an expression of the form d=ax3/2 , where a= 1.0 m-1/2. the sides are well insulated, while the top surface of the cone at x1 is maintained at t1 and the bottom surface at x2 is maintained at t2 . what is the rate of heat transfer across the cone if it is constructed of pure aluminum with x1= 0.075 m, t1= 135°c, x2= 0.225 m, and t2= 20°c? evaluate the properties of aluminum at t¯= 333 k

The mass flow rate of the fluid remains constant in all steady flow process. a)- true b)- false

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2