The three essential navigational tools on fifteenth-century ships were

a. world maps, charts of latitude and longitude, and magnetic compasses.
b. Portolan charts, clocks, and the astrolabe.
c. dead reckoning, Portolan charts, and quadrants.
d. Portolan charts, magnetic compasses, and the astrolabe.


d. Portolan charts, magnetic compasses, and the astrolabe.

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Air at 52°C, 101.3 kPa, and 20 percent relative humidity enters a 5-cm-diameter tube with an average velocity of 6 m/s. The tube inner surface is wetted uniformly with water, whose vapor pressure at 52°C is 13.6 kPa. While the temperature and pressure of air remain constant, the partial pressure of vapor in the outlet air is increased to 10 kPa. Detemine (a) the average mass transfer coefficient in m/s, (b) the log-mean driving force for mass transfer in molar concentration units, (c) the water evaporation rate in kg/h, and (d) the length of the tube.

What will be an ideal response?

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Overcharging a system reduces its efficiency by:

A) Increasing the system superheat. B) Starving the evaporator. C) Decreasing the system subcooling. D) Increasing the operating head pressure and compression ratio.

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Which one of the following is not a binary arithmetic function?

A) Division B) Multiplexing C) Addition D) Subtraction

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Nine, old, 12 ft^2 windows with U= 1.2 Btu/ hr·ft^2·? were replaced with new windows having U = 0.3 Btu/ hr·ft^2·? . Calculate the energy savings on a day during a 5-hour period, when Tin = 68ºF, Toutside = 10ºF.

What will be an ideal response?

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