Abusiness school has a goal that the average number of years of work experience of its mba applicants is more than three years. historical data suggest that the variance has been constant at around six months, and thus, the population variance can be assumed to be known. based on last year’s applicants, it was found that among a sample of 47, the average number of years of work experience is 3.1. can the school state emphatically that it is meeting its goal? formulate the appropriate hypothesis test and conduct the test.

Ahe-xe mixture containing a 0.75 mole fraction of helium is used for cooling electronics in an avionics application. at a temperature of 300 k and atmospheric pressure, calculate the mass fraction of helium and the mass density, molar concentration and molecular weight of the mixture. if the cooling capacity is 10 l, what is the mass of the coolant?

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.

What is creep? what is stress relaxation?