Afilm of paint 3 mm thick is applied to a surface inclined above the horizontal at an angle \theta. the paint has rheological properties of a bingham plastic with yield stress 15 pa and \mu[infinity]= 60 cp. with a specific gravity of 1.3, at what angle \ theta will the paint start to flow down the surface?

Steel is coated with a thin layer of ceramic to protect against corrosion. what do you expect to happen to the coating when the temperature of the steel is increased significantly? explain.

What is the heat treatment of metals? what is the benefit of it? why and how it's useful? answer in details, do not write by hand.

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.