The following two functions have a common input, year t:
I gives the projected amount of natural gas imports in quadrillion Btu, and E gives the projected natural gas exports in trillion Btu.

(a) Using function notation, show how to combine the two functions to create a third function, N, giving net trade of natural gas in year t.
(b) What does negative net trade indicate?

Acompressor receives the shaft work to decrease the pressure of the fluid. a)- true b)- false

For the closed feedwater heater below, feedwater enters state 3 at a pressure of 2000 psia and temperature of 420 °f at a rate of ix10 ibhr. the feedwat extracted steam enters state 1 at a pressure of 1000 psia and enthalpy of 1500 btu/lbm. the extracted er leaves at an enthalpy of 528.7 btu/lbm steam leaves as a saturated liquid. (16) a) determine the mass flow rate of the extraction steam used to heat the feedwater (10) b) determine the terminal temperature difference of the closed feedwater heater

Machinery that is a key part of the process and without which the plant or process cannot function is classifed as: (clo4) a)-critical machinery b)-essential machinery c)-general purpose machinery d)-none of the specified options.