1) in many civil engineering calculations, water and other liquids are assumed to be incompressible. do you think this assumption is reasonable? a. report the bulk modulus of water and seawater at 60°f. b. use the definition of the bulk modulus to determine the amount of pressure in psi needed to change the density of freshwater and seawater by 5%. which one is more easily compressed? c. compare the results from part b with values for standard atmospheric pressure and for the pressure at the bottom of the mariana trench (15,750 psi). under what conditions does the incompressible assumption fail?

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?