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?

Air is to be cooled in the evaporator section of a refrigerator by passing it over a bank of 0.8-cm-outer-diameter and 0.4-m-long tubes inside which the refrigerant is evaporating at -20°c. air approaches the tube bank in the normal direction at 0°c and 1 atm with a mean velocity of 4 m/s. the tubes are arranged in-line with longitudinal and transverse pitches of sl- st 1.5 cm. there are 30 rows in the flow direction with 15 tubes in each row. determine (a) the refrigeration capacity of this system and (b) pressure drop across the tube bank. evaluate the air properties at an assumed mean temperature of -5°c and 1 atm. is this a good assumption?

Ariver flows from north to south at 8 km/h. a boat is to cross this river from west to east at a speed of 20 km/h (speed of the boat with respect to the earth/ground). at what angle (in degrees) must the boat be pointed upstream such that it will proceed directly across the river (hint: find the speed of the boat with respect to water/river)? a 288 b. 21.8 c. 326 d. 30.2

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