A brick of 203 × 102 × 57 mm in dimension is being burned in a kiln to 1600°C, and then allowed to cool in a room with ambient air temperature of 30° C and convection heat transfer coefficient of 5 W/m^2·K. The brick has properties of rho = 1920 kg/m^3, cp = 790 J/kg·K, and k = 0.90 W/m·K.
Determine the time required to cool the brick to a temperature difference of 5°C from the ambient air temperature.

Explain the difference laminar and turbulent flow. explain it with the shear stress and the velocity profiles.

Apump is used to circulate hot water in a home heating system. water enters the well-insulated pump operating at steady state at a rate of 0.42 gal/min. the inlet pressure and temperature are 14.7 lbf/in.2, and 180°f, respectively; at the exit the pressure is 60 lbf/in.2 the pump requires 1/15 hp of power input. water can be modeled as an incompressible substance with constant density of 60.58 lb/ft3 and constant specific heat of 1 btu/lb or. neglecting kinetic and potential energy effects, determine the temperature change, in °r, as the water flows through the pump.

Shafts are machine elements that are used to a) carry axial loads b) direct shear loads c) transmit power d) rotate at constant speed e) none of the above circular and square shafts subjected to the same torque under the same circum behave a) the same way b) almost the same way