GEAS 56

What is the equation for the work done by a constant temperature system?

• A. W = mRTln(V2-V1)

• B. W = mR( T2-T1 ) ln( V2/V1)

• C. W = mRTln (V2/V1)

• D. W = RT ln (V2/V1)

Twenty grams of oxygen gas are compressed at a constant temperature of 30 ˚C to 5%of their original volume. What work is done on the system.

• A.824 cal

• B.924 cal

• C.944 cal

• D.1124 cal

Helium ( R= 0.4698 BTU/lbm-˚R ) is compressed isothermally from 14.7 psia and 68 ˚F. The compression ratio is 1:4. Calculate the work done by the gas.

• A. –1454 BTU/lbm

• B. -364 BTU/lbm

• C.-187BTU/lbm

• D.46.7 BTU/lbm

Gas is enclosed in a cylinder with a weighted piston as the stop boundary. The gas is heated and expands from a volume of 0.04 m^3 to 0.10 m^3 at a constant pressure of 200kPa.Calculate the work done by the system.

• A. 8 kJ

• B. 10 kJ

• C.12 kJ

• D.14 kJ

refer to problem no.4. Determine the specific volume.

• A. 0.02 ft^3/lbm

• B. 0.05 ft^3/lbm

• C. 1.0 ft^3/lbm

• D. 1.2 ft^3/lbm

What is the weight of a66-kgm man at standard condition?

• a. 66 kgf

• b. 66 kgm

• c. 66 lbm

• d. 66 gf

What is the specific weight of water at standard condition?

• a. 1000 kgm/m3

• b. 9.8066 m/s2

• c. 1000 kgf/m3

• d. None of the above

746 °R = ______ °F

• a. 254

• b. 345

• c. 286

• d. None of the above

A 30-m vertical column of fluid (density 1878 kg/m3 ) is located where g= 9.65 mps2. Find the pressure at the base of the column.

• a. 543680 N/m2

• b. 543.68 kPa (gauge)

• c. Both a & b

• d. None of the above

Ten cu ft. of air at 300 psia 400°F is cooled to 140°F at constant volume. What is the final pressure?

• a. 0

• b. 209 psia

• c. – 420 psia

• d. None of the above