What is most nearly the change in enthalpy per kg of nitrogen gas as its temperature changes from 260°C to 93°C (Cp = 1.04 kJ/kg-K)?

What is most nearly the resulting pressure when 400 g of air at 103.6 kPa and 93°C is heated at constant volume to 427°C?

Approximately how much power is required to isothermally compress 23 m3 /min of air from 101.5 kPa to 828.5 kPa?

A piston-cylinder system contains a gas that expands under a constant pressure of 57 kPa. If the piston is displaced 0.3 m during the process, and the piston diameter is 0.6 m, what is the work done by the gas on the piston?

In an isentropic compression, p1 = 2.14 N/cm2 , p2 = 4.28 N/cm2 , V1 = 164 cm3 , and the ratio of specific heats is k = 1.4. What is most nearly the value of V2?

In an adiabatic, isentropic process, p1 = 4.28 N/cm2 , p2 = 6.42 N/cm2 , and T1 = 388K. The ratio of specific heats is 1.4. What is most nearly the value of T2?

Find the density of air at vacuum of 40 kPa and -40°C in kg/cu.m. Assume 1 atm = 100 kPa.

If air is at a pressure, p, of 135 Pa, and at a temperature, T, of 440K, what is most nearly the specific volume, v? (Air's specific gas constant is R = 88.81 J/kg.K, and air can be modeled as an ideal gas.)

Steam at 416 Pa and 166K has a specific volume of 0.41 m3 /kg and a specific enthalpy of 29.4 kJ/kg. Find the internal energy per kilogram of steam.

1.36 kg of air are held at 6.89 kPa and 38°C. Given that Rair = 88.89 J/kg.K, what is most nearly the volume of the container?

What is most nearly the change in internal energy of 2.27 kg of oxygen gas when the temperature changes from 38°C to 49°C? (Cv = 0.658 kJ/kg-K)

Water (specific heat Cv = 4.2 kJ/kg-K) is being heated by a 1500 W heater. What is most nearly the temperature rate of change for 1 kg of water?

Air undergoes an isentropic compression from 0.31 N/cm2 to 3.87 N/cm2 . If the initial temperature is 20°C and the final temperature is 327.5°C, what is most nearly the work done by the gas?

Nitrogen is expanded isentropically. Its temperature changes from 600K to 288K. Find the pressure ratio (P1/P2).

An engine burns a liter of fuel each 12 min. The fuel has a specific gravity of 0.8 and a heating value of 45 MJ/kg. The engine has an efficiency of 25%. What is most nearly the brake horsepower of the engine?

A Carnot refrigerator operates between two reservoirs. One reservoir is at higher temperature Th and the other is at cooler temperature Tc. What is the coefficient of performance COP of the refrigerator?

A refrigeration system produces 348.9kJ/kg of cooling. In order to have a rating of 1 ton of refrigeration, what must be the mass low rate of the vapor? (1 ton of refrigeration = 12.66 MJ/hr, approximately the rate required to freeze 2000 lbm of ice in one day).

What is the ideal compression ratio of an Otto cycle that uses air as the gas and has an efficiency of 50%?

A Carnot engine operates between 444K and 555K. What is the thermal efficiency?

Scientist have recently developed a power pulse laser for research in materials. Find its energy output in watts for the following conditions, when at its peak pulse, it will produced 10 terawatts for period of 10psec. Find the discharged in joules.

Calculate the energy required by an electron to reach 90% of the speed of light starting from rest.

Shaft work of -15 BTU/lb and heat transfer of -10 BTU/lb change enthalpy of a system by

A 200-mL flask contained oxygen at 200 torr and a 300 mL flask contained nitrogen at 100 torr. The two flasks were then interconnected so that each gas filled its combined volumes. Assuming no change in temperature, what was the total pressure?

Two vessels A and B of different sizes are connected by a pipe with a valve. Vessel A contains 142 L of air at 2767.92 kPa, 93.33 deg C. Vessel B, of unknown volume, contains air at 68.95 kPa, 4.44 deg C. The valve is opened and when the properties have been determined, it is found that pm = 1378.96 kPa. tm = 43.33 deg C. What is the volume of vessel B?

During a polytropic process, 10 lb of an ideal gas, whose R = 40 ft-lbf/lbm-deg and cp = 0.25 BTU/lb-deg R, changes state from 20 psia and 40 deg F to 120 psia and 340 deg F. Determine AU.

The maximum thermal efficiency that can be obtained in an ideal reversible heat engine operating between 1540 deg F and 340 deg F is?

Compute the maximum possible efficiency of heat engine operating between temperature limits of 100 deg C and 400 deg C.

A temperature of 100 deg F is almost exactly,

A ladder 3.0m long ang weighing 200 N has its center of gravity 1.2 cm from the bottom. At its top end is a 50-N weight. Compute the work required to raise the ladder from a horizontal position on the ground to a vertical position.

A refrigerator is rated at COP of 4. The refrigerated space that it cools requires a peak cooling rate of 30,000 kJ/h. What is the size of the electrical motor (rated in horsepower) required for the refrigerator?

Energy is added to a piston cylinder arrangement and the piston is withdrawn in such a way that the quantity PV remains constant. The initial pressure and volume are 200 kPa and 2 cu. respectively. If the final pressure is 100 kPa calculate the work done by the gas on the piston.

The work of a polytropic (n = 1.21) compression of air (Cp / Cv = 1.4) in a system with moving boundary from P1 = 15 psia, V1 = 1.0 ft^3 to P2 = 150 psia, V2 = 0.15 ft^3 is

Calculate the work done by a piston if the 2 cu m volume of air is tripled while the temperature is maintained at 40 degree C, the initial pressure is 400 kPa.

A small pumps up his bicycle tires on a day when a temperature is 300 K. Find the temperature of the air in the bicycle pump if the tire pressure are to be 24.5 lb/sq in and the air in the pump is assumed to be compressed adiabatically. For air k = 1.40.

A Carnot refrigerator absorbs 600 BTU at the low temperature, the delivers 1000 BTU to the high temperature, reservoir. Find its coefficient of performance,

A 200 ton train is accelerated from rest to a velocity of 30 miles per hour on a level track. How much useful work was done?

The temperature of a body is 50 deg F. Find its temperature in deg C.

The heat loss per hour through 1 sq.ft of furnace wall 18’’ thick is 520 Btu. The inside wall temperature is 1900 deg F, and its average thermal conductivity is 0.61 Btu/hr ft deg F. Determine the outside surface temperature of the wall.

A 2 kg block is dropped from height of 40 cm onto a spring onto a spring whose force constant k is 1960 N/m. Find the maximum distance the spring will be compressed.

Air at 27 deg C is heated to 927 deg C. Find the change in enthalpy, treating air as a perfect gas (cp and cv constant) cp = 1.00 and cv = 0.718,

A piston allows air to expand from 6 kPa to 200 Pa. The initial volume and temperature are 0.5 m^3 and 800 deg C. If the temperature is held constant, calculate the heat transfer.

An iron plate 2 cm thick has a cross of 5000 sq.cm. One face is at 150 deg C and the other is at 140 deg C. How much heat passes through the plate each second? For iron kT = 80 w/m-k,

In a certain process 500 cal of heat are supplied to a system and at the same time 100 joules of work are done. What is the increase in the internal energy of the system?

A 2 lbm at 200 deg F iron (Cp = 0.1 BTU/lbm-deg F) are dropped into a gallon of 40 deg F of water. What is the final temperature of the mixture?

Air having an initial pressure P1 = 14 psia, temperature T1 = 80 deg F, and volume V1 = 28 cu.ft is compressed isentropically in a non flow process to a final pressure Pf = 120 psia. The final temperature is nearest to

If a 1/3 horsepower pump runs for 20 minutes, what is the energy used?

Energy is added to 5 kg air with a paddle wheel so that ΔT = 100 deg C while P = constant in an insulated container. The paddle wheel work is

A 1.0 slug mass has a kinetic energy of 1.0 ft-lb when its speed is

A Carnot engine operated between reservoirs at 20 deg C and 200 deg C. If 10 kW of power is produced, the rejected heat rate is nearest

How much external work is done by an ideal has expanding from a volume of 3.0 liters to a volume of 30.0 liters against a constant pressure of 2.0 atm.

What is the ideal compression ratio of an Otto cycle that uses air as the gas and has an efficiency of 50%?

A refrigeration system produces 348.9kJ/kg of cooling. In order to have a rating of 1 ton of refrigeration, what must be the mass low rate of the vapor? (1 ton of refrigeration = 12.66MJ/hr, approximately the rate required to freeze 2000lb of ice in one day).

A refrigerator has a COP of 4 and can remove 20,000kJ/hr of heat from a cold body. Find the hp of the motor.

Nitrogen is expanded isentropically. Its temperature changes from 600K to 288K. Find the pressure ratio (p1/p2).

Air undergoes an isentropic compression from 0.31N/cm^2 to 3.87N/cm^2. If the initial temperature is 20°C and the final temperature is 327.5°C, what is most nearly the work done by the gas?

In an adiabatic, isentropic process, pl = 4.28N/cm^2, p2 = 6.42N/cm^2 and T1 = 388K. The ratio of specific heats is 1.4. What is most nearly the value of T2?

In an isentropic process, pl=2.14Ncm^2, p2 = 4.28N/cm^2, V1 = 164 cc and the ratio of specific heats is k= 1.4. What is most nearly the value of V2?

If air is at a pressure of 135Pa ad temperature of 440K, what is most nearly the specific volume? Air's gas constant is 88.81J/kg-K and air can be modelled as an ideal gas.

1.36kg of air are held at 6.89kPa and 38°C. Given that Rair = 88.89J/kg-K, what is most nearly the volume of the container?

What is most nearly the change in internal energy of 2.27kg of oxygen gas when the temperature changes from 38°C to 49°C? Cv = 0.658kJ/kg-K.

Water, Cv=4.2kJ/kg-K is being heated by a 1500W heater. What is most nearly the temperature rate of change for 1kg of water?

Approximately how much power is required to isothermally compress 23m^3/min of air from 101.5kPa to 828.5kPa?

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

What is most nearly the energy of a photon of wavelength 0.1nm?

Solar collectors generates 1kW/m^2 of thermal energy using the sun's energy. A collector with an area of 1m^2 heats water. The water flow rate is 30L/min. What is most nearly the temperature rise in the water? The sp. heat of water is 4200J/kg-°C.

A copper sphere 0.3m in diameter radiates power through a vacuum to an environment at 273K. The emissivity of copper is 0.15 and the sphere is at 60°C. The power radiated is most nearly

A home has brick walls 15mm thick. On a cold winter day, the temperature of the inner and outer surfaces of the walls are found to be 20°C and -12°C respectively. There is 120m^2 of exterior wall space. The thermal conductivity of brick is 0.711J/m-s -°C. Most nearly how much heat is lost through the walls per hour?

In a constant temperature closed system process, 100BTU of heat are transferred to the working fluid at 100°F. What is the change in entropy of the working fluid?

If the average in a nuclear reaction is 200MeV/fission, what is the power output of a reactor experiencing 2.34x10^19 fissions/s?