Flexing Members

210 lb

A flat belt is 6 inches wide and 1/3 inch thick and transmits 20 Hp. The center distance is 8 ft. The driving pulley is 6 inches in diameter and rotates at 2 000 rpm such that the loose side of the belt is on top. The driven pulley is 18 inches in diameter. The belt material is 0.035 lb/in3 and the coefficient of friction is 0.30. Determine the belt net tension.

2.578

A pulley 600 mm in diameter transmits 40 kW at 500 rpm. The arc of contact between the belt and pulley is 155o, the coefficient of friction between belt and pulley is 0.35 and the safe working stress of the belt is 2.1 MPa. Determine the belt tensions ratio, neglecting the effect of centrifugal force.

303.3 mm

Two shafts 3.6 m between centers carry pulleys 1.2 m in diameter and 0.91 m in diameter respectively, connected by a crossed belt. It is desired to put the belt on as an open belt. How long a piece must be cut of it?

87.97 %

A 20-kW motor, running at 1200 rpm, drives a 400 mm diameter pulley at a belt tension ratio of 2.4. If the belt’s tight side tension is only 1200 N, determine the transmission efficiency.

RC 60

What is the largest roller chain size that can be used for power transmission at a sprocket speed of 1000 rpm?

212 pitches

A 20-tooth motor sprocket, running at 1200 rpm, drives a blower at a speed ratio of 4:1. Using the largest permissible chain size and the largest permissible center distance of 80 pitches, what length of chain in pitches is required to connect the sprockets?

2505 N

A pulley 610 mm in diameter transmits 40 KW at 500 rpm. The arc of contact between the belt and the pulley is 0.35 and the safe working stress of the belt is 2.1 MPa. Find the tangential force at the rim of the pulley in Newton.

2505 N

A pulley 610 mm in diameter transmits 40 KW at 500 rpm. The arc of contact between the belt and pulley is 144 degrees, the coefficient of friction between belt and pulley is 0.35 and the safe working stress of the belt is 2.1 and the safe working stress of the belt is 2.1 MPa. What is the effective belt pull in Newton.

4.24

A band brake is installed on a drum rotating at a 250 rpm, and a diameter of 900 mm. the angle of contact is 1.5 pi radians and one end of the brake band is fastened to a fixed pin while the other end to the brake arm 150 mm from the fixed pin. The coefficient of friction is 0.25 and the straight brake arm is 1000 mm long and is placed perpendicular to the diameter bisecting the angle of contact. Determine the net belt pull in kN applied at the kilowatts is being absorbed.

55 hp

A leather belt 6 inches wide by ¼ in thick running at 4000 ft/min connects 12 in and 60 in. in diameter pulleys. The angles of contact are 270 deg. and 240 deg. for small and large pulleys respectively. Coefficient of friction on large pulley is 0.4 on small pulley 0.3. if the allowable tension is 100lb per in. determine the maximum horsepower that can be transmitted without considering centrifugal force.

800 lbs

A 10" diameter pulley is belt driven with a net torque of 250 ft-lbs. The ratio of tensions in the tight to stack sides of the belt is 4 to 1. What is the maximum tension in the belt?

169.87 deg

An air compressor is driven by a 7.5 HP electric motor with a speed of 1750 rpm with A-60 V-belts of length 61.3 in. the pitch diameter of the small sheave is 110mm and the larger sheave is 200 mm. service factor is 1.2. determine the arc of contact.

2505 N

A pulley 610 mm in diameter transmits 40 KW at 500 rpm. The arc of contact between the belt and the pulley is 0.35 and the safe working stress of the belt is 2.1 MPa. Find the tangential force at the rim of the pulley in Newton.

2505 N

A pulley 610 mm in diameter transmits 40 KW at 500 rpm. The arc of contact between the belt and pulley is 144 degrees, the coefficient of friction between belt and pulley is 0.35 and the safe working stress of the belt is 2.1 and the safe working stress of the belt is 2.1 MPa. What is the effective belt pull in Newton.

291.66 lb and 340 hp

A 4 inches diameter shaft is driven at 3600 rpm by a 400 Hp motor. The shaft drives a 48 inches diameter chain sprocket having an output efficiency of 85%. The output force of the driving sprocket and the output of the driven sprocket are:

69

A certain farm equipment which requires 2200 Newton mater torque at 500 RPM has a diesel engine to operates at 1500 RPM as its prime mover. A No. 60 roller chain with a total length of 60 pitches and a small sprocket with 23 teeth are to be used with an operating temperature to remain constant at 45-degree C. Determine the no. of teeth of the larger sprocket.

300N

The efficiency of a set of chain driven differential pulley blocks is 35% when lifting a load of 1.89kN. If the large and small pulleys of the compound sheave have 27 teeth respectively, find the effort required to lift this load.

5

In a set of rope pulley blocks which has 3 pulleys in the top block and 2 in the bottom, an effort of 300 N is required to lift a load of 1.26 kN. Find the velocity ratio.

500N

There are four pulleys in each block of a set of rope pulley blocks. If the efficiency is 70% when lifting a load of 2.8 kN, what is the effort applied?

2 x 10⁶ kJ

A 10 m3 vessel contains 5 m3 of liquid water and 5 m3 of saturated water vapor at 100kpa. Calculate the internal energy of the system using the steam tables.

24.9 ft³

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?

1124 cal

Twenty grams of oxygen (O2) are compressed at a constant temperature of 30°C to 5 % of their original volume. What work is done on the system?

3.16 kg

A vessel with a volume of 1 cubic meter contains liquid water and water vapor equilibrium at 600 kPa. The liquid water has a mass of 1 kg. Using the steam tables, calculate the mass of the vapor.

-432 kJ/kg

A cylinder and a piston arrangement contains saturated water vapor at 110 °C. The vapor is compressed in a reversible adiabatic process until the pressure is 1.6 MPa. Determine the work done by the system per kilogram of water.

0

Ideal Oxygen is throttled at 140degF from 10 atm to 5 atm. What is the temperature change?

8 kJ

Gas is enclosed in a cylinder with a weighted piston as the top boundary. The gas is heated and expands from a volume of 0.04 m3 at a constant pressure of 200 kPa. Calculate the work done by the system.

6.74 x 10^-20 J

Assume the total heat of vaporization (per gram) of water can be used to supply the energy needed to tear 1 g of water molecules apart from each other. How much energy is needed per molecule for this purpose?

230.4 BTU/lbm

An isobaric steam generating process starts with saturated liquid at 20 psia. The change in entropy is equal to the initial entropy. What is the change in enthalpy during the process? (Hint: Not all liquid is vaporized.)

The device violates the 1st law of thermodynamics.

A steam generator produces saturated steam at 100 psia from saturated liquid at 14.7 psia. If the heat source is a bath at 340F that produces 800 BTU/lbm, which of the following is true?

13.3 ft³/lbm

If air is at a pressure, ρ , of 3200 lbf/ft2, and at a temperature, T , of 800°R, what is the specific volume, v? (R = 53.3 ft-lbf/lbm-°R, and air can modeled as an ideal gas)

100,000 kJ

A 5m3 vessel initially contains 50 kg of lquid water and saturated water vapor at total internal energy of 27,3000 kJ. Calculate the heat requirement to vaporize all of the liquid.

100 J

A copper can of negligible heat capacity contains 1 kg of water just above the freezing point. A similar can contains 1 kg of water just below the boiling point. Two cans are brought to into thermal contact. Find the change in entropy of the system?

1.66 x 10^-24 g/atom

The atomic weight of hydrogen is 1gram per gram-atom. What is the mass of hydrogen atom?

755 mmHg

In a gaseous mixture of 20 deg. C the partial pressures of the components are as follows: Hydrogen, 200 mmHg; Carbon Dioxide, 150 mmHg; Methane, 320 mmHg; Ethylene, 105 mmHg. What is the total pressure of the mixture?

-94.8 BTU/lbm

Air undergoes an isentropic compression from 14.7 psia to 180.6 psia. If the initial temperature is 68 °F and the final temperature is 621.5 °F, calculate the work done by the gas.

7.33 kJ

Gas is enclosed in a cylinder with a weighted piston as the top boundary. The gas is heated and expands from a volume 0.04 m3 to 0.1 m3. The pressure varies such that PV = C, and the initial pressure is 200 kPa. Calculate the work done by the system.

1.79 kJ/kg.°C

From the steam tables, determine the average constant pressure specific heat (Cp) of steam at 10 kPa and 45.8°C.

2.39 J/moleK

For an ideal gas, what is the specific molar entropy change during an isothermal process in w/c the pressure changes from 200 kPa to 150 kPa?

Zero

What is the value of the work done for a closed, reversible, isometric system?

2585 psia

If 1 lbm of steam at 14.7 psia, 63 % quality is heated isentropically, at what pressure will it reach the saturated vapor state?

348.0 cal/K

200g of water are heated from 5C to 100C and vaporized at a constant pressure. The heat of vaporization of water at 100C is 539.2 cal/g. The heat capacity at constant pressure, Cp is 1.0 cal/gK. Determine the total change in entropy.

n = 0

What is true about the polytropic exponent, n , for a perfect gas undergoing an isobaric process?

0.91

On a hot day, the temperature rises from 50F early in the morning to 99F in the afternoon. What is the ratio of the concentration (in moles/ft3 of helium in a spherical balloon in the afternoon to the concentration of helium in the balloon in the morning?

4.18 kW

Cool water at 9 deg. C enters hot-water from which warm water at a temperature of 80 deg. C is drawn at an average rate of 300 g/min. How much average electric power does the heater consume in order to provide hot water at this rate?

0.357 K/s

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

700 kJ

Calculate the change in enthalpy as 1 kg of nitrogen is heated from 1000 K to 1500 K, assuming the nitrogen is an ideal gas at a constant pressure. The temperature-dependent specific heat of nitrogen is:

cp = 39.06 - 512.79T^-1.5 + 1072.7T^-2 - 820.4T^-3

cp is in kJ/Kmole-K and T is in K.

-0.689 BTU/lbm-°R

Helium is compressed isothermally from 14.7 psia and 60 °F. The compression ratio is 4. Calculate the change in entropy of the gas given that RHe = 0.4961 BTU/lbm-°R.

75.4 K

One kilogram of water (cv = 4.2 kJ/kg-K) is heated by 300 BTU of energy. What is the change in temperature, in K?

6.095 in³

In an isentropic compression, p1 = 200 psia, p2 = 300 psia, V1 = 10 in3, and k= 1.4. Find V2.

179.3 ml

200 mL of oxygen are collected over water at 23C and a pressure of 1 atmosphere. What volume would the oxygen occupy dry at 273K and 1 atmosphere?

7.28 atm

A gas has a density of 0.094 lb/ft3 at 100degF and 2 atm. What pressure is needed to change the density to 0.270 lb/ft3 at 250degF?

8.342 psia

If atmospheric air 14.7 psia and 60degF at sea level, what is the pressure at 12000 ft altitude if air is incompressible. Note: @ 60degF; the density of air is 0.0763 lbm/ft3; P1 = 14.7 psia

23.57 psia

A cold tire contains 1000 in.3 of air at 24 psia and 32degF. What pressure in the tire is needed if the temperature and volume are increased to 35degF and 1020 in.3 respectively?

1.67

Determine the specific gravity of carbon dioxide gas (molecular weight = 44) at 150degF (66degC) and 20 psia (138 kPa).

7544 ft³

An empty polyethylene telemetry balloon and payload have a mass of 500 lbm. The balloon is charged with helium when the atmospheric conditions are 60degF and 14.8 psia. The specific gas constant of helium is 386.3 ft-lbf/lbm-R. What is the volume of helium is required?

12.12 kJ/K

What is the change in entropy of 2 kg water molecules when transformed at constant pressure of 1 atmosphere from water at 100degC to steam at the same temperature?

0.026

In a gaseous mixture of 20 deg. C the partial pressures of the components are as follows: Hydrogen, 200 mmHg; Carbon Dioxide, 150 mmHg; Methane, 320 mmHg; Ethylene, 105 mmHg. What is the mass fraction of Hydrogen ( m(H2) = 2, m(CO2) = 44, m(meth) = 16 and m(eth) = 30 kg/mol) ?

13.1

Assume the total heat of vaporization (per gram) of water can be used to supply the energy needed to tear 1 g of water molecules apart from each other. What is the ratio of energy needed per molecule to kT where k = 1.38 x 10-23 J/K?

3300 lbf-ft/lbm

Steam at 1000 lbf/ft2 pressure and 300°R has a specific volume of 6.5 ft3/lbm and a specific enthalpy of 9800 lbf-ft/lbm. Find the internal energy per pound mass of steam.

1.1577 BTU/lbm-°R

Calculate the entropy of steam at 60 psia with a quality of 0.6.

15.7 BTU

Find the change in internal energy of 5 lbm of oxygen gas when the temperature changes from 100°F to 120°F. cv = 0.157 BTU/lbm-°R.

-74.49 BTU/lbm

Determine the change in enthalpy per lbm on nitrogen gas as its temperature changes from 500°F to 200°F. cp = 0.2483 BTU/lbm-°R.

28.6 psia

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

108 Hp

What horsepower is required to isothermally compress 800 ft3 of air per minute from 14.7 psia to 120 psia?

3050 kJ

Calculate the work done by a system in which 1 kg mole of water completely evaporates at 100°C and 1 atmosphere pressure.

W = mRTln V₂/V₁

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

3768 ft-lbf

A piston-cylinder system contains a gas which expands under a constant pressure of 1200 lbf/ft2. If the piston is displaced during the process, and the piston diameter is 24”, what is the work done by the gas on the piston?

Both: heat transfer = 0; Isentropic: reversible.

How does an adiabatic process compare to an isentropic process?

786 °R

In an adiabatic, isentropic process, p1 = 200 psia, p2 = 300 psia, and T1 = 700 °R. Find T2, using γ= 1.4.

12.9

Nitrogen is expanded isentropically. Its temperature changes from 620 °F to 60 °F. Find the pressure Ratio (p1/p2).

99.22 BTU/lbm

Nitrogen is expanded isentropically. Its temperature changes from 620 °F to 60 °F. The volumetric ratio is V2/V1 = 6.22 and the value of R for nitrogen is 0.0787 BTU/lbm-°R. What is the work done by the gas?

III

A device that is meant to extract power from waste process steam starts w/ steam of 75% quality at 100 psia. The exit conditions of the steam are 70% quality at 14.7 psia. Which of the following statements are true?

I. The device violates the 1st law of thermodynamics.

II. The device violates the 2nd law of thermodynamics.

III. The device generates positive net power.

IV. The device generates no net power.

I and II

An engineer devices a scheme for extracting some power from waste process steam. The steam enters a device at 100 psi and quality 75% and exits at 14.7 psia and 65% quality. Which of the following statements are true?

I. The produces 155 BTU/lbm of work.

II. The device violates 2nd law of thermodynamics.

III. The device violates the 1st law of thermodynamics.

5.98 g

A bicycle tire has a volume of 600 cm3. It is inflated with CO2 to a pressure of 80 psi at 20C. How many grams of CO2 are contained in the tire?

49.2 g

When 0.5 g of a liquid is completely evaporated and collected in a 1 liter manometer, the pressure is 0.25 atmospheres and the temperature is 27C. Assuming ideal behaviour, determine the molecular weight. The gas constant is R=0.0821 atm/moleK.

0.895 cu. m.

A 0.064 kg octane vapor (MW = 114) is mixed 0.91 kg of air (MW = 29.0) in the manifold is 86.1 kPa, and the temperature is 290 K. Assume octane behaves ideally, what is the total volume of this mixture?

1.197 kg/m³

Determine the sp.heat weight of air at 760 mmHg absolute and 22C?

371.56

How long could a 2000 hp motor be operated on the heat energy liberated by 1 mi.3 of ocean of water when the temperature of the water is lowered by 1degC and if all these heat were converted to mechanical energy?

0.23 BTU/lbR

Given that molar Cp of CO2 is 8.92 BTU (lb.moleR) and molar Cp of N2 is 6.95 BTU/(lbmoleR), the calculated Cp per pound of mixture containing 25% vol. CO2 and 75% vol. N2 is:

3.15

A mixture at 14.7 psia and 68F that is 30% weight CO2 (m wt=44) and 7% wt. N2 (m wt=28) has a partial pressure of CO2 in psia that is nearest to:

162R

Normal boiling point of liquid oxygen is 90K. What is its temp in R?

+5 BTU/lb

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

+6.7

A non-flow (closed) closed system contains 1lb of an ideal gas (Cp = 0.24, Cv = 0.17). The gas temperature is increased by 10F while 5 BTU of work are done by the gas. What is heat transfer in BTU?

49

55,000 gallons of water passes through a heat exchanger and absorbs 28,000,000 BTU’s. The exit temperature is 110F. The entrance water temperature in F is nearest to:

5150 ft-lb

Work of polytropic (n=1.21) compression of air ( Cp/Cv = 1.40) in a system moving boundary from P1 = 15 psia V1 = 1.0 ft3 to P2 = 150 psia V2 = 0.15 ft3.

mCv (T₂ - T₁) + Pa(V₂ - V₁)

A cylinder fitted with a weightless, frictionless piston contains m pounds of air at temperature T1 volume V1, and ambient pressure Pa. Heat is added until the air in the cylinder has a temperature T2, a volume V2, and ambient pressure Pa. The specific heat of air at constant volume is Cp, the specific heat of air at constant volume is Cv. The heat transferred during the process is:

12.8 BTU/lb

A high velocity flow gas at 800 ft/sec possesses kinetic energy nearest to which of the following?

0.32 ft³

Isentropic compression of 1 ft3 of air (Cp/Cv = 1.40), at 20 psia to 100 psia gives a final volume of:

609kj/kg

Find the work possess for a helium gas at 20C.

Ethane

Two kilogram of gas is confined in a 1m^3 tank 200kpa and 88degC. What type of gas is in the tank?

333.42 KJ/kg

Find the enthalpy of the helium if its internal energy is 200KJ/Kg.

9.47

Compute the mass of a 2m^3 propane at 280 kpa and 40degC

9.46kg

Find the mass of 10 quartz of water

1.24 lbs

Find the mass of carbon dioxide having a pressure of 20 psia at 200F with 10ft^3 volume.

1,647.29 kj/kg

Find the heat needed to raise the temperature of water from 80^C to 100^C with 60% quality. Consider an atmospheric pressure of 101.325 kpa. Use the approximate enthalpy formula of liquid.

471 Btu/lb

Find the enthalpy of water 212F and 14.7 psi dryness for factor is 30% use the approximate enthalpy formula of liquid.

115.55 deg C

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

416.33K

Convert 750R to K

0

Air is compressed adiabatically from 30degC to 100degC. If mass of air being compressed is 5kg, Find the change of entropy?

0

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