Steam at 1000 lbf/ft^2 pressure and 300˚R has specific volume of 6.5 ft^3/lbm and a specific enthalpy of 9800 lbf-ft/lbm. Find the internal energy per pound mass of steam.  A.2500 lbf-ft/lbm  B.3300 lbf-ft/lbm  C.5400 lbf-ft/lbm  D.6900 lbf-ft/lbm Formula: h= u+ pV u= h– pV

1 Answer

Answer :

3300 lbf-ft/lbm

Related questions

Description : If air is at pressure, p, of 3200 lbf/ft2 , and at a temperature, T, of 800 ˚R, what is the specific volume, v? (R=5303 ft-lbf/lbm-˚R, and air can be modeled as an ideal gas.)  A.9.8 ft^3/lbm  B.11.2 ft^3/lbm  C.13.33 ft^3/lbm  D.14.2 ft^3/lbm Formula: pv = RT v = RT / p

Last Answer : 13.33 ft^3/lbm

Description : 3.0 lbm of air are contained at 25 psia and 100 ˚F. Given that Rair = 53.35 ft-lbf/lbm- ˚F, what is the volume of the container?  A.10.7 ft^3  B.14.7 ft^3  C.15 ft^3  D.24.9 ft^3 Formula: use the ideal gas law pV = mRT T = (100 +460) ˚R V = mRT/p

Last Answer : 24.9 ft^3

Description : Find the change in internal energy of 5 lb. of oxygen gas when the temperature changes from 100 ˚F to 120 ˚F. CV = 0.157 BTU/lbm-˚R  A.14.7 BTU  B.15.7 BTU  C. 16.8 BTU  D. 15.9 BTU Formula: U= mcv T

Last Answer : 15.7 BTU

Description : Find ∫ for steam at 100 psia and 600°F.If h = 1329.6 and v = 6.216  a. 1214 Btu / lb  b. 1234 Btu /lb  c. 1342 Btu / lb  d. 1324 Btu /lb formula: ∫ = h– pv/ J

Last Answer : 1214Btu / lb

Description : The flow energy of 5 ft3 of a fluid passing a boundary to a system is 80,000 ft-lb. Determine the pressure at this point.  a. 222 psi  b. 333 psi  c. 444 psi  d. 111 psi formula: Ef= pV

Last Answer : 111 psi

Description : If value of n is infinitely large in a polytropic process pV” = C, then the process is known as constant  (a) volume  (b) pressure  (c) temperature  (d) enthalpy  (e) entropy

Last Answer : Answer : a

Description : Calculate the entropy of steam at 60psiawith a quality of 0.8  A. 0.4274 BTU/lbm-˚R  B. 0.7303 BTU/lbm-˚R  C. 1.1577 BTU/lbm-˚R  D. 1.2172 BTU/lbm-˚R Formula: fromthe steamtable at 60 psia: sƒ = 0.4274 BTU/lbm-˚R sƒg = 1.2172 BTU/lbm-˚R) s = sƒ + x sƒg where x = is the quality

Last Answer : 1.1577 BTU/lbm-˚R

Description : The sum of internal energy (U) and the product of pressure and volume (p.v) is known as  A. workdone  B. entropy  C. enthalpy  D. none of these

Last Answer : Answer: C

Description : Sum of the internal energy of a substance and the product of pressure and volume.  a. Specific Heat  b. Specific Gravity  c. Isolated System  d. Enthalpy

Last Answer : Enthalpy

Description : The unit of gcis (A) lbm/lbf. ft/sec2 (B) lbf/lbm. ft/sec2 (C) ft/sec2 (D) lbm/lbf. sec2/ft

Last Answer : (A) lbm/lbf. ft/sec2

Description : A problem Drum ( 3 ft. diameter ; 6 ft. height ) is field with a fluid whose density is 50 lb/ft^3. Determine the total volume of the fluid.  A. 42.41 ft^3  B.44.35 ft^3  C.45.63 ft^3  D.41.23 ft^3 Formula: Vf = (pi d^2 h) / 4

Last Answer : 42.41 ft^3

Description : A 10m^3 vessel initially contains 5 m^3 of liquid water and 5 m^3 of saturated water vapor at 100 kPa. Calculate the internal energy of the system using the steam table.  A. 5 x10^5 kJ  B. 8x10^5 kJ  C. 1 ... 3 kJ/kg ug= 2506kJ/kg formula: Mvap = V vap/vg M liq = Vliq/ vƒ u =uƒM liq + ug M vap

Last Answer : 2 x10^6 kJ

Description : The weight of an object is 50lb. What is its mass at standard condition?  a. 50 lbm  b. 60 lbm  c. 70 lbm  d. 80 lbm formula: m = Fgk /g

Last Answer : 50 lbm

Description : Assuming compression is according to the Law PV = C, Calculate the initial volume of the gas at a pressure of 2 bars w/c will occupy a volume of 6m³ when it is compressed to a pressure of 42 Bars.  a) 130m³  b) 136m³  c) 120m³  d) 126m³ Formula: P1V1/T1 =P2V2/T2

Last Answer : 126m³

Description : Which of the following parameters is constant for a mole for most of the gases at a given temperature and pressure  (a) enthalpy  (b) volume  (c) mass  (d) entropy  (e) specific volume.

Last Answer : Answer : b

Description : From the steam table, determine the average constant pressure specific heat (c) of steam at 10 kPa and45.8 ˚C  A.1.79 kJ/ kg-˚C  B.10.28 kJ/ kg-˚C  C.30.57 kJ/ kg-˚C  D. 100.1 kJ/ kg-˚C Formula: h = c T ∆ ∆ From the steam table At 47.7 ˚C h= 2588.1 kJ/ kg At 43.8 ˚C h= 2581.1 kJ/ kg

Last Answer : 1.79 kJ/ kg-˚C

Description : What mass of nitrogen is contained in a10 ft3 vessel at a pressure of 840atm and 820°R? Make a computation by using ideal gas equation.  a. 194lb  b. 214lb  c. 394 lb  d. 413lb formula: m=pV /RT

Last Answer : 394 lb

Description : What is the resulting pressure when one pound of air at 15 psia and 200 ˚F is heated at constant volume to 800 ˚F?  A.15 psia  B. 28.6 psia  C. 36.4 psia.  D. 52.1 psia Formula : T1/p1 = T2/p2 p2= p1T2 / T1

Last Answer : 28.6 psia

Description : Change in enthalpy in a closed system is equal to heat transferred if the reversible process takes place at constant  (a) pressure  (b) temperature  (c) volume  (d) internal energy  (e) entropy.

Last Answer : Answer : a

Description : Which of the following is the property of a system  (a) pressure and temperature  (b) internal energy  (c) volume and density  (d) enthalpy and entropy  (e) all of the above.

Last Answer : Answer : e

Description : For which of the following substances, the internal energy and enthalpy are the functions of temperature only  (a) any gas  (b) saturated steam  (c) water  (d) perfect gas  (e) superheated steam.

Last Answer : Answer : d

Description : What is the weight of a66-kgm man at standard condition? (Formula: Fg= mg / k)  a. 66 kgf  b. 66 kgm  c. 66 lbm  d. 66 gf

Last Answer : 66 kgf

Description : 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 Formula: W = RT ln (V2/V1)

Last Answer : -364 BTU/lbm

Description : Ten cu ft. of air at 300 psia 400°F is cooled to 140°F at constant volume. What is the final pressure? (formula: p2 = p1T2/T1)  a. 0  b. 209 psia  c. - 420 psia  d. None of the above

Last Answer : 209 psia

Description : A vessel with a volume of cubic meter contains liquid water and water vapor ion equilibrium at 600 kPa. The liquid water has mass of1kg. Using the steam table, calculate the mass of the water vapor.  A. 0.99kg  B. 1.57 kg  C ... / kg vg = 0.3157 m^3 / kg Vtot = mƒ vƒ + mg vg mg = (tot-mƒ vƒ) / vg

Last Answer : 3.16 kg

Description : Which of the following processes are thermodynamically reversible  (a) throttling  (b) free expansion  (c) constant volume and constant pressure  (d) hyperbolic and pV = C  (e) isothermal and adiabatic.

Last Answer : Answer : e

Description : A system having a rigid boundary that energy, work and mass does not cross its boundaries  a. Specific Heat  b. Specific Gravity  c. Isolated System  d. Enthalpy

Last Answer : Isolated System

Description : Which of the following statements is TRUE for an ideal gas, but not for a real gas?  A. PV = nRT  B. An increase in temperature causes an increase in the kinetic energy of the gas  C. The ... same as the volume of the gas as a whole  D. No attractive forces exists between the molecule of a gas

Last Answer : PV = nRT

Description : Ten cu. ft of air at 300psia and 400°F is cooled to 140°F at constant volume. What is the transferred heat?  a.-120Btu  b. -220Btu  c.-320Btu  d. -420Btu formula: Q= mcv(T2-T1)

Last Answer : -420Btu

Description : Steam is throttled to 0.1 MPa with 20 degrees of superheat. (a) What is the quality of throttled steam if its pressure is 0.75 MPa (b) What is the enthalpy of the process?  a) 97.6%,2713 kJ/kg  b) -97.6%, 2713 kJ/kg  c) 87.6%,3713 kJ/kg  d) -87.6%, 3713 kJ/kg

Last Answer : 97.6%,2713 kJ/kg

Description : Gas being heated at constant volume is undergoing the process of.  a. isometric  b. specific heat  c. enthalpy  d. isothermal

Last Answer : isometric

Description : _____ is that property of a substance which remains constant if no heat enters or leaves the substance, while it does work or alters its volume, but which increases or diminishes should a small amount of heat enter or leave.  a. Entrophy  b. Enthalpy  c. Specific Heat  d. None of the above

Last Answer : Entrophy

Description : What horse power is required to isothermally compress 800 ft^3 of Air per minute from 14.7 psia to 120 psia?  A. 28 hp  B.108 hp  C.256 hp  D.13900 hp Formula: W= p1V1 ln (p1/p2) Power = dW / dt

Last Answer : 108 hp

Description : According to kinetic theory of gases, the absolute zero temperature is attained when  (a) volume of the gas is zero  (b) pressure of the gas is zero  (c) kinetic energy of the molecules is zero  (d) specific heat of gas is zero  (e) mass is zero.

Last Answer : Answer : c

Description : A certain gas, with cp = 0.529Btu/ lb. °Rand R = 96.2ft.lb/lb. °R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5psia. Compute for T2.  a.1520°R  b. 1620°R  c. 1720°R  d. 1820°R formula: T2= T1V2/V1

Last Answer : 1620°R

Description : A certain gas, with cp = 0.529Btu/lb.°R and R = 96.2 ft.lb/lb.°R, expands from 5 cu ft and 80°F to 15 cu ft while the pressure remains constant at 15.5 psia. Compute for T2. (Formula: T2= T1V2/V1)  a. 460°R  b. 270°R  c. 1620 °R  d. None of the above

Last Answer : 1620 °R

Description : The heat Q per unit mass per degree change in temperature that must be supplied or removed to change the temperature of a substance.  a. Specific Heat Capacity  b. Latent Heat  c. Heat of Transformation  d. Internal Heat

Last Answer : Specific Heat Capacity

Description : A vertical column of water will be supported to what height by standard atmospheric pressure. If the Y w = 62.4lb/ft3 po = 14.7 psi.  a. 44.9 ft  b. 33.9 ft  c. 22.9 ft  d. 55.9 ft formula: ho= po/Yw

Last Answer : 33.9 ft

Description : Entropy is the measure of:  a. The internal energy of a gas  b. The heat capacity of a substance  c. Randomness or disorder  d. The change of enthalpy of a system

Last Answer : Randomness or disorder

Description : Which of the following occurs in a reversible polytrophic process?  a. Enthalpy remains constant  b. Internal energy does not change  c. Some heat transfer occurs  d. Entropy remains constant

Last Answer : Some heat transfer occurs

Description : What happens to the internal energy of water at reference temperature where enthalpy is zero?  a. Becomes negative  b. Becomes positive  c. Remains constant  d. Cannot be defined

Last Answer : Becomes negative

Description : What is the measure of the energy that is no longer available to perform useful work within the current environment?  a. enthalpy  b. entropy  c. internal energy  d. latent heat

Last Answer : entropy

Description : What is known as the total heat and heat content at various times in the history?  a. enthalpy  b. entropy  c. internal energy  d. latent heat

Last Answer : enthalpy

Description : In an isothermal process,  A. there is no change in temperature  B. there is no change in enthalpy  C. there is no change in internal energy  D. all of these

Last Answer : Answer: D

Description : If heat be exchanged in a reversible manner, which of the following property of the working substance will change accordingly  (a) temperature  (b) enthalpy  (c) internal energy  (d) entropy  (e) all of the above.

Last Answer : Answer : d

Description : Total heat of a substance is also known as  (a) internal energy  (b) entropy  (c) thermal capacity  (d) enthalpy  (e) thermal conductance.

Last Answer : Answer : d

Description : According to first law of thermodynamics  (a) work done by a system is equal to heat transferred by the system  (b) total internal energy of a system during a process remains constant  ( ... , enthalpy and entropy during a process remain constant  (d) total energy of a system remains constant

Last Answer : Answer : d

Description : Change in enthalpy of a system is the heat supplied at  (a) constant pressure  (b) constant temperature  (c) constant volume  (d) constant entropy  (e) N.T.P. condition.

Last Answer : Answer : a

Description : What predicts the approximate molar specific heat at high temperatures from the atomic weight?  A. Third law of thermodynamics  B. Law of Dulong and Petit  C. Mollier diagram  D. Pressure-enthalpy diagram

Last Answer : Law of Dulong and Petit

Description : Mass (not weight) per unit volume  a. Specific Weight  b. Specific Volume  c. Density  d. None of the above

Last Answer : Density