Estimate how long will it will take to cool a trailer filled with coke. given the ambient temperature is 20 °c and heat transfer provided by the refrigeration unit is 25kw and the drinkable temperature is 5 °c. make reasonable estimates of how much insulation is included on the walls of the truck. assume the coke cans are stacked in rows inside the truck with sufficient space for air to circulate between them. assume an air flow velocity inside the truck of 0.35 m/s. assume the sun is incident on the external surface of the truck for part of the time. indicate any assumptions you make in your analysis. take the properties of coke as: specific heat capacity 4000 j/kgk, density 1000 kg/m3 and thermal conductivity of 0.5 w/mk

Two flowing streams of argon gas are adiabatically mixed to form a single flow/stream. one stream is 1.5 kg/s at 400 kpa and 200 c while the second stream is 2kg/s at 500 kpa and 100 ? . it is stated that the exit state of the mixed single flow of argon gas is 150 c and 300 kpa. assuming there is no work output or input during the mixing process, does this process violate either the first or the second law or both? explain and state all your assumptions.

Burgers vector is generally parallel to the dislocation line. a)-true b)-false

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?