A slender rodAB, of weightW, is attached to blocksAandB, which move freely in the guidesshown. The blocks are connected by an elastic cord that passes over a pulley atC. (a) Expressthe tension in the cord in terms ofWand. (b) Determine the value offor which the tension inthe cord is equal to3W.

An air conditioning system consist of a 5 cm diameter pipe, operating at a pressure of 200 kpa. the air initially enters the pipe at 15°c with a velocity of 20 m/s and relative humidity of 80%. if the heat supply throughout the process is 960 w, determine the relative humidity and the temperature at the outlet

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.

The sum of the normal stresses does not change as the stress state rotates through an angle. a)-trune b)- false