A thermocouple junction of spherical form is to be used to measure the temperature of a gas stream. h = 400w/m^2 deg C; k(thermocouple junction) = 20 w/m deg C; cp = 400 J/kg deg C; and density = 8500 kg/m^3; Calculate the following: i. Junction diameter needed for the thermocouple to have the thermal time constant of one second. ii. Time required for the thermocouple junction to reach 198 deg C if junction is initially at 25 deg C and is placed in gas stream which is at 200 deg C.

Consider the loaded shaft illustrated in Figure Q4 (i). The shaft is simply supported at A and D. The shoulder fillet radius is 0.3 cm at B and C. If the shaft is subjected to a force of F=800 N, determine the following:

Liquid nitrogen has a density of 0.808 g/mL and boils at 77 K. Researchers often purchase liquid nitrogen in insulated 175-L tanks. The liquid vaporizes quickly to gaseous nitrogen (which has a density of 1.15 g/L at room temperature and atmospheric pressure) when the liquid is removed from the tank. Suppose that all 175 L of liquid nitrogen in a tank accidentally vaporized in a lab that measured 10.00m x 10.00m x 2.50m. What maximum fraction of the air in the room could be displaced by the gaseous nitrogen?

only first attempt please