In a brief report, discuss why we need various modes of transportation. How did they evolve? Discuss the role of public transportation, water transportation, highway transportation, railroad transportation,
and air transportation.

Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.

Afluid flows with a velocity field given by v=(x/t)i.. determine the local and convective accelerations when x=3 and t=1.

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