A general aviation aircraft has a propeller with 75 inches diameter that rotates at 2300 rpm (revolution per minute). Find the Mach number at the tip when the aircraft is standing on the ground ready to take off

The higher the astm grain size number, the finer the gran is. a)-true b)-false

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.