When can the conductive thermal resistance of the tube in a heat exchanger be neglected in overall heat transfer coefficient calculation? Never When the tube is thin or the material is highly conductive When the tube is thin.     When the tube material is highly conductive.           Which of the following sentence(s) is/are true? We cannot calculate thermal resistance of a solid slab. Thermal resistance concept is applicable only in Cartesian or Cylindrical coordinate.   We cannot calculate ther

The following figure shows a coffee thermos as a lumped thermal system. Derive the symbolic expression using the given parameters for the temperature change rate of the coffee dT/dt (10 Ambient Temperature Ta Thermos Thickness L Surface area A Conductivity k Connectivity with air h₂ Coffee Temperature T Thermal capacitance C Connectivity with the thermos h₁

36 -S 42 2. Metal castings can sometimes develop a gap between the casting and mold as the molten metal hardens. The result can be a substantially altered cooling process. Set up a simple heat-transfer model that would let you look at the effect of the gap on the cooling process. Assume the casting and mold are square in shape, with an air gap of thickness das shown in the figure. The mold sits in some ambient room temperature. State clearly all assumptions and develop a corresponding model of the heat transfer problem. Assuming that the casting is aluminum, the mold is diatomaceous earth and the gap is filled with air, see if you can arrive at and summarize some insight into the effect of the gap and its size on the heat transfer process.

subject (differential equation) pls show me full steps with clear handwriting sir pls answer me in 10 mins sir  urgent pls