A heat engine has a thermal efficiency of 50%. How much power does the engine produce when heat is transferred at a rate of 109 kJ/hr?

A water tube boiler has a capacity of 1000 kg/hr of steam. The factor of evaporation is 1.3, boiler rating is 200%, boiler efficiency is 65% and heating surface area is 0.91 m² per bo.Hp. And the heating value of fuel is 18,400 kCal/kg. The total coal available in the bunker is 50,000 kg. Determine the no. of hrs. to consume the available fuel.

Aluminum has a specific heat of 0.902 J/g-°C. How much heat is lost when a piece of aluminum with a mass of 23.984 g cools from a temperature of 415.0°C to a temperature of 22.0°C?

Find the mass of 10 quartz of water.

Calculate the air power of a fan that delivers 1200 m³/min of air through a 1 m x 1.5 m outlet. Static pressure is 120 mm WG and density of air is 1.18.

At a pressure of 60°F, a motorbike Ire is inflated to 33 psig. As it is driven along the C-5 road, the temperature rose to 76°F. Assuming the volume remains constant, determine the final gauge pressure. Given: P1 = 33 psig + 14.7 psig = 47.7 psig T1 = 60°F + 460 = 520°R T2 = 76°F + 460 = 536°R

The specific weight of liquid is 60 lb/ft³. What is the equivalent to kN/m³?

A gas turbine power plant operating on the Brayton cycle delivers 15 MW to a standby electric generator. What are the mass flow rate and the volume flow rate of air if the minimum and maximum pressures are 100 kPa and 500 kPa respectively and temperature of 20°C and 1000°C?

Consider a refrigerator whose 40 watts light bulb remains on continuously as a result of a malfunction of the switch. If the refrigerator has a COP of 1.3 and the cost of electricity is 8 cents per kW-hr, determine the increase in the energy consumption of the refrigerator and its cost per year if the switch is not fixed.

In an open feedwater heater for a steam plant, saturated steam at 7 bar is mixed with subcooled liquid at 7 bar and 25°C. Just enough steam is supplied to ensure that the mixed steam leaving the heater will be saturated liquid at 7 bar when heater efficiency is 95%. Calculate the mass flow rate of the subcooled liquid if steam flow rate is 0.865 kg/s. Steam properties: @ 7 bar, saturated vapor: hg = 2763.5 kJ/kg @ 7 bar and 25°C: hf = 105.5 kJ/kg @ 7 bar, saturated liquid: hf = 697.22 kJ/kg

A tank contains 90 ft³ of air at a pressure of 350 psig; if the air is cooled until its pressure and temperature decreases at 200 psig and 70°F respectively, what is the decrease in internal energy?

Determine the number of stages needed for a centrifugal pump if it is used to deliver 400 gal/min of water and pump power of 15 hp. Each impeller develops a head of 30 ft.

A logging firm in Isabella operates a Diesel Electric Plant to supply its electric energy requirements. During a 2 hour period, the plant consumed 250 gallons of fuel at 80°F and produced 2900 kW-hrs. Industrial fuel is used at 30°API and was purchased at P30/li at 60°F. Determine the overall thermal efficiency of the plant.

A water reservoir contains 100,000 kg of water at an average elevation of 60 m. The maximum amount of electric power that can be generated from this water is ?

If the temperature of an air parcel is -20.5°C, and its density is 0.690 kg/m³ , what is the pressure of the air parcel?

A 300 mm diameter pipe discharges water at a rate of 200 li/s. Point 1 on the pipe has a pressure of 260 kPa and 3.4 m below point 1 is point 2 with a pressure of 300 kPa. Compute the head loss between points 1 and 2.

A thermal power plant generates 5 MW and the heat generated by fuel is 13,000 kJ/s. If the thermal efficiency is 36.15%, find the power needed for the auxiliaries.

An empty, open can is 30 cm high with a 15 cm diameter. The can, with the open end down, is pushed under water with a density of 1000 kg/m³. Find the water level in the can when the top of the can is 50 cm below the surface.

Two liters of an ideal gas at a temperature of T1 = 25°C and a pressure of P1 = 0.101 MPa, are in a 10 cm diameter cylinder with a piston at one end. The piston is depressed so that the cylinder is shortened by 10 centimeters. The temperature increases by 2°C. What is the change in pressure?

What is the resulting pressure when one pound of air at 15 psia and 200°F is heated at constant volume to 800°F?

Determine the pressure exerted on a diver at 30 m below the free surface of the sea. Assume a barometric pressure of 101 kPa and the specific gravity of sea water is 1.03.

A water-jacketed air compressor handles 0.343 m³/s of air entering at 96.5 kPa and 21°C and leaving at 480 kPa and 132°C; 10.9 kg/hr of cooling water enters the jacket at 15°C and leaves at 21°C. Determine the compressor brake power.

A copper bar is 90 centimeters long at 86°F. What is the increase in its length when the bar is heated to 95°F? The linear expansion coefficient for copper, α, is 1.7 x 10-⁵/°C.

Methyl alcohol (CH3OH) is burned with 25% excess air. How much unburned oxygen in kg- moloxygen/kg-molfuel will there be in the products if the combustion is complete?

A 75 hp motor that has an efficiency of 91% is worn out and is replaced by a high-efficiency motor that has an efficiency of 95.4%. Determine the reduction in heat gain of the room due to higher efficiency under full-load conditions.

A 29.53” x 39.37” pressure vessel contains ammonia with f = 0.041. Compute the minimum required discharge capacity of the relief device in kg/hr.

Two kilogram of gas is confined in a 1 m3 tank at 200 kPa and 88°C. What type of gas is in the tank?

It is desired to double the COP of a reversed Carnot engine for cooling from 5.0 by raising the temperature of heat addition while keeping the temperature of heat rejection constant. By what percentage must the temperature of heat addition be raised?

Steam turbine is receiving 1014 lbm/hr of steam, determine the horsepower output of the turbine if the work done by steam is 251 Btu/lbm.

Pressure difference of 400 Pa is available to force 20°C air through a circular sheet-metal duct 450 mm in diameter and 25 m long. At 20°C, ρ = 1.204 kg/m³and take friction factor, f = 0.016. Determine the velocity.

Steam leaves an industrial boiler at 827.4 kPa and 171.6°C. A portion of the steam is passed through a throttling calorimeter and is exhausted to the atmosphere when the calorimeter pressure is 101.4 kPa. How much moisture is leaving the boiler container if the temperature of the steam at the calorimeter is 115.6°C? @ 827.4 kPa and 171.6°C: hf = 727.25 kJ/kg hfg = 2043.2 kJ/kg @ 101.4 kPa and 115.6°C: h2 = 2707.6 kJ/kg

The brake thermal efficiency of a 1 MW diesel electric plant is 36%. Find the heat generated by fuel in kW if the generator efficiency is 89%.

A reverse Carnot cycle requires 3 Hp and extracts energy from a lake to heat a house. If the house is kept at 70°F and requires 2000 Btu per minute, what is the temperature of the lake?

What is the pressure at point A in the tank if h = 2 feet? (g = 32.2 ft/s² and ρ = 1.94 slug/ft³)

In an actual refrigeration cycle using R12 as working fluid, the refrigerant flow rate is 0.05 kg/s. Vapor enters the expansion valve at 1.15 MPa, 40°C (h = 238.5 kJ/kg) and leaves the evaporator at 175 kPa, -15°C (h = 345 kJ/kg). The electric iput to motor driving the compressor is measured and found 3.0 kW. Motor efficiency at this load 92% and mechanical efficiency 82%. Determine the actual coefficient of performance for this cycle.

The initial condition of air in an air compressor is 98 kPa and 27 °C and discharges air at 450 kPa. The bore and stroke are 355 mm and 381 mm, respectively with percent clearance of 8% running at 300 rpm. Find the volume of air at suction.

A 650 BHP diesel engine uses fuel oil of 28°API gravity, fuel consumption is 0.65 lb/BHP-hr. Cost of fuel is P7.95 per liter. For continuous operation determine the minimum volume of cubical day tank in cm³, ambient temperature is 45° C.

Find the length of a suspension bunker to contain 181 tons of coal without surcharge; width = 4.6 m, depth = 4.3 m. The level capacity of a suspension bunker is 5/8 wdL where: w = width, d = depth and L = length. Density of coal is 800 kg/m3.

Find the heat needed to raise the temperature of water from 30°C to 100°C with 60% quality. Consider an atmospheric pressure of 101.325 kPa. Use the approximate enthalpy formula of liquid.

A barometer can be used to measure an airplane’s altitude by comparing the barometric pressure at a given flying altitude to that on the ground. Determine an airplane’s altitude if the pilot measures the barometric pressure at 700 mm-Hg, the ground reports it at 758 mm-Hg, and the average air density is 1.19 kg/m3 , g = 9.81 m/s2 .

A 4 m³/hr pump delivers water to a pressure tank. At the start, the gage read 138 kPa until it reads 276 kPa and then the pump was shut off. The volume of the tank is 180 liters. At 276 kPa, the water occupied 2/3 of the tank volume. Determine the volume of the water that can be taken out until the gage reads 138 kPa.

A 1.5 kg of wet steam at a pressure of 5 bar (hf = 640 kJ/kg, hfg = 2109 kJ/kg) dryness 0.95 is blown into 70 liters of water 12°C (h = 50.4 kJ/kg). Find the final enthalpy of the mixture.

In an ideal Otto cycle, air is compressed from 1.20 kg/m3 and 2.2 L to 0.26 L and the net work output of the cycle is 440 kJ/kg. The mean effective pressure for the cycle is?

A two-stage, double acting compressor is to deliver 90 lb/min of air from 14.3 psia to 90°F to a final pressure of 185 psia. The normal barometer is 29.8 in-Hg and the temperature is 80°F. The pressure drop in the intercooler is 3 psi and the speed is 210 rpm and pV1.34 = C during compression and expansion. The clearance is 5% for both cylinders. Find the volume of free air if the temperature of the cooling water increased by 18°F.

If the gage pressure of a medium is 30 kPa (vacuum) and the atmospheric pressure is 101.3 kPa, the absolute pressure will be?

A rectangular duct has a dimension of 0.25 m by 2 m. Determine the equivalent diameter of the duct.

A Carnot cycle has a maximum temperature of 550°F and minimum temperature of 100°F. If the heat added is 4200 Btu/min, find the horsepower output of the engine.

Determine the force in newton in a piston of 465 mm² area with a pressure of 0.172 MPa.

A current of 7 amperes passes through a 12 ohm resistor. What is the power dissipated in the resistor?

Two kilogram of air in a rigid tank changes its temperature from 32°C to 150°C. Find the work done during the process.

A 50 kg block of iron casting at 500 K is thrown into a large lake that is at a temperature of 285 K. The iron block eventually reaches thermal equilibrium with the lake water. Assuming average specific heat of 0.45 kJ/kg-K for the iron, determine the entropy generated during this process.

How many poles should a 60-Hz generator have, if it is connected to a turbine operating under a design head of 3000 ft with a flow of 82 cfs? Assume turbine specific speed and efficiency 3 and 84 percent respectively.

A Carnot cycle operates between the temperature limits of 300 K and 1500 K, and produces 600 kW of net power. The rate of entropy change of the working fluid during heat addition process is?

Oil flows through a 16 tube single cooler with a velocity of 2 m/s. The internal diameter of the tube is 30 mm and oil density is 0.85 gm/ml. Find the volume flow in liters per sec.

During a reversible process, there are abstracted 317 kJ/s from 1.134 kg/s of a certain gas while the temperature remains constant at 26.7°C. For this gas cp = 2.232 and cv = 1.713 kJ/kg-K. The initial pressure is 586 kPa. Determine the final volume flow rate.

An insulated steam pipe located where the ambient temperature is 32°C, has an inside diameter of 50 mm with 10 mm thick wall. The outside diameter of corrugated asbestos insulation is 125 mm and the surface coefficient of still air, ho = 12 W/m²-K. Inside the pipe is steam having a temperature of 150°C with film coefficient hi = 6000 W/m²-K. Thermal conductivity of pipe and asbestos insulation are 45 and 0.12 W/m-K respectively. Determine the heat loss per unit length of pipe.

Find the thrust and efficiency of two 2-m diameter propellers through which flows a total of 600 m³/s of air to 11.3 N/m³.The propellers are attached to an airplane moving at 250 kph through still air. Neglect eddy losses.

A gaseous fuel mixture has a molal analysis: H2 = 14% CH4 = 3% CO = 27% O2 = 0.6% CO2 = 4.5% N2 = 50.9% Determine the air-fuel ratio for complete combustion on molal basis.

If the load on water-cooled condenser is 150,000 Btu/hr and the temperature rise of the water in the condenser is 10°F, what is the quantity of water circulated in gpm?

A turbine receives 150 lbm/s of air at 63 psia and 2450°R and expands it polytropically to 14.7 psia. The exponent n is equal to 1.45 for the process. Determine the power.

A mixture of 0.4 lbm of helium and 0.2 lbm of oxygen is compressed polytropically from 14.7 psia and 60°F to 60 psia according to n = 1.4. Determine the final temperature, T 2.

Water (ρ = 62.4 lbm/ft³) is flowing through a pipe. A pitot-static gage registers 3.0 inches of mercury. What is the velocity of the water in the pipe? Note: ρHg = 848.6 lbm/ft3³ .

A car engine with a power output of 65 hp has a thermal efficiency of 24%. Determine the fuel consumption rate of this car if the fuel has a heating value of 19,000 Btu/lbm.

The gas density of chimney is 0.75 kg /m³ and air density of 1.15 kg /m³ .Find the driving pressure if the height of the chimney is 63.71 m

The dry exhaust gas from the oil engine has the following gravimetric analysis: CO2 = 21.6% O2 = 4.2% N = 74.2% Specific heats at constant pressure for each component of the exhaust gas in kCal/kg-°C are: CO2 = 0.203 O2 = 0.219 N = 0.248 Calculate the specific gravity if the molecular weight of air is 28.97 kg/kg-mol.

What force is exerted by a water jet, 60 mm in diameter, if it strikes a wall at the rate of 15 m/s?

Kerosene is pumped into an aircraft fuel tank through a hose that has an inside diameter of 4 cm. If the velocity of the kerosene is 8 m/s through the hose, determine the mass flow rate. Assume that the kerosene has a density of 800 kg/m³.

An impulse wheel at best produces 125 hp under a head of 210 ft. By what percent should the speed be increased for a 290-ft head?

A bicycle tire has a volume of 600 cm3 . It is inflated with carbon dioxide to pressure of 551.43 kPa, 20°C. How many grams of CO2 are contained in the tire? RCO2 = 0.18896 kJ/kg.K.

The gain of entropy during isothermal nonflow process of 5 lb of air at 60°F is 0.462 Btu/°R. Find the V1/V2.

A vertical furnace wall is made up of an inner wall of firebrick 20 cm thick followed by insulating brick 15 cm thick and an outer wall of steel 1 cm thick. The surface temperature of the wall adjacent to the combustion chamber is 1200°C while that of the outer surface of steel is 50°C. The thermal conductivities of the wall material in W/m-K are: firebrick, 10; insulating brick, 0.26; and steel, 45. Neglecting the film resistances and contact resistance of joints, determine the heat loss per sq.m. of wall area.

A nozzle receives 0.5 kg/s of air at a pressure of 2700 kPa and a velocity of 30 m/s and with an enthalpy of 923 kJ/kg, and the air leaves at a pressure of 700 kPa and with an enthalpy of 660 kJ/kg. Determine the exit velocity from the nozzle.

A single-stage ammonia compressor is producing 10 tons of refrigeration and the power consumed is 15 Hp. Suction pressure is 25 psi, condensing pressure is 180 psi. Brine temperature is 20°F off brine cooler. Determine the actual coefficient of performance.

A house is maintained at 22°C in winter by electric resistance heaters. If the outdoor temperature is 5°C, the second law efficiency of the resistance heaters is ?

In order to cool 1 ton (1000 kg) of water at 20°C in an insulated tank, a person pours 80 kg of ice at -5°C into the water. Determine the final equilibrium temperature in the tank. The melting temperature and the heat of fusion of ice at atmospheric pressure are 0°C and 333.7 kJ/kg, respectively.

What is the approximate value of temperature of water having enthalpy of 208 Btu/lb?

Find the density of oil with a specific gravity of 1.6 in-g/cm³.

A pressure cooker operates by cooking food at a higher pressure and temperature possible at atmospheric conditions. Steam is contained in the sealed pot, with vent hole in the middle of the cover, allowing steam to escape. The pressure is regulated by covering the vent hole with a small weight, which is displaced slightly by escaping steam.Atmospheric pressure is 100 kPa, the vent hole area is 7-mm², and the pressure inside should be 250 kPa. What is the mass of the weight?

The specific speed of turbine is 85 rpm and running at 450 rpm. If the head is 20 m and generator efficiency is 90%, what is the maximum power delivered by the generator?

A water temperature rise of 18°F in the water cooled condenser is equivalent to what in °C?

Fuel oil in a day tank for use of an industrial boiler is tested with hydrometer. The hydrometer reading indicates a SG = 0.924 when the temperature of the oil in the tank is 35°C. Calculate the higher heating value of the fuel.

The charge in a Diesel engine consists of 18.34 grams of fuel, with lower heating value of 42,571 kJ/kg, and 409 grams of fuel and products of combustion. At the beginning of compression, T1 = 60°C. Let rk = 14. For constant cp = 1.11 kJ/kg-°C, what should be the cut-off ratio in the corresponding ideal cycle?

A refrigerating system operates on the reversed Carnot Cycle. The higher temperature of the refrigerant in the system is 120°F and the lower is 10°F. The capacity is 20 tons. Neglect losses. Determine the coefficient of performance.

What is the work required to accelerate an 800-kg car from rest to 100 km/h on a level road?

A cylindrical flash tank mounted with its axis horizontal is used to separate liquid ammonia from ammonia vapor. The ammonia bubbles through the liquid with 70 m³/min leaving the disengaging surface. The disengaging rate is limited to 60 m/min and the liquid level is to operate with the liquid level one-third to the diameter from the top. Determine the diameter if the tank is 1.5 m long.

A mixture of 0.4 lbm of helium and 0.2 lbm of oxygen is compressed polytropically from 14.7 psia and 60 °F to 60 psia according to n = 1.4. Determine the polytropic work.

A diesel engine consumed 945 liters of fuel per day at 35°C. If the fuel was purchased at 15.6°C and 30°API at P29.00/li. Determine the cost of fuel to operate the engine per day.

The lower half of a 10 m high cylindrical container is filled with water and the upper half with oil that has SG = 0.85. Determine the pressure difference between the top and bottom of the cylinder.

Steam expands adiabatically in a turbine from 2000 kPa, 400°C to 400 kPa, 250°C. What is the effectiveness of the process in percent assuming an atmospheric pressure of 18°C? Neglect changes in kinetic and potential energy. Steam properties: @ 2000 kPa and 400°C: h = 3247.6 kJ/kg s = 7.1271kJ/kg-K @ 400 kPa and 250°C: h = 2964.2 kJ/kg s = 7.3789 kJ/kg-K

A tank contains liquid nitrogen at -190°C is suspended in a vacuum shell by three stainless steel rods of 0.80 cm in diameter and 3 meters long with a thermal conductivity of 16.3 W/m²-°C. If the ambient air outside the vacuum shell is 15°C, calculate the magnitude of the conductive heat flow in watts along the support rods.

A rigid tank contains 20 lbm of air at 20 psia and 70°F. More air is added to the tank until the pressure and temperature rise to 35 psia and 90°F, respectively. Determine the amount of air added to the tank.

Water is pumped at 1 m³/s to an elevation 5 meters through a flexible hose using a 100% efficient pump rated at 100 kilowatts. Using the same length of hose, what size motor is needed to pump 1 m³/s of water to the tank, with no elevation gain? In both cases, both ends of thehose are at the same temperature and pressure. Neglect kinetic energy effects.

A pump delivers 20 cfm of water having a density of 62 lb/ft³. The suction and discharge gage reads 5 in. Hg vacuum and 30 psi respectively. The discharge gage is 5 ft above the suction gage. If pump efficiency is 70%, what is the motor power?

At 1.3 MPa, a mixture of steam and water has an entropy of 3 kJ/kg-K, Find the enthalpy of the mixture. @ 1.3MPa: sf = 2.2515 kJ/kg-K sg = 6.4952 kJ/kg-K hf = 814.93 kJ/kg hfg = 1972.7 kJ/kg

A diesel cycle, which takes in air at 1 bar and 26°C, has a compression ratio of 19. Calculate the operating clearance in percent.

Determine the mass of water vapor contained in a 150 m³ room at 100 kPa, 23°C and 40% relative humidity. From Steam Tables: Psat @ 23°C = 2.810 kPa.

A volumetric analysis of a gas mixture is a follows: CO2: 12% O2: 4% N2: 80% CO: 4% What percentage of CO2 on a mass basis?

In a hydro-electric plant, water flows at 10 m/s in a penstock of 1 m3³ cross-sectional area. If the net head of the plant is 30 m and the turbine efficiency is 85%, what is the turbine output?