# 73118568-GeAS

October 3, 2017 | Author: Coronia GeMzon Neil | Category: Stress (Mechanics), Thermal Conduction, Heat, Yield (Engineering), Second Law Of Thermodynamics

#### Description

GEAS REVIEWER 1.) An investor has an option to purchase a tract of land that will be worth P20,000 in seven years. If the value of the land increases at 9% each year, how much should the investor be willing to pay now for this property?

8.) A plant bought a machine for P200,000 and used it for 10 years, the life span of the equipment. What is the book value of the machine after 5 years of use? Assume a scrap value of P20,000. Use double declining balance method.

a. P9,341

a. P43,648

b. P10,941

c. P11,521

d. P12,015

b. P36,218

c.

37,954

a. b.

Direct shear Bending stress

c. Torsional shear d. Torsional stress.

10.) It occurs when a member carries a load perpendicular to its long axis while being supported in a stable manner.

d. P38,755

 (1  i ) n  1   F  A i   = P2000(F/A,8%,12)  P37,954.25

a. Direct shear b.Bending stress

c. Torsional shear d. Torsional stress

11.) It is the internal resistance offered by a unit area of the material from which a member from which a member is made to an externally applied load. a. stress

3.) What is the effective rate of interest if P1000 is invested at a nominal rate of 15% compounded quarterly? b. 16.86%

d. P70,923

9.) It occurs when a cutting action is applied as you would see with scissors, tin snips, or punches.

2.) Suppose that you make 12 equal annual deposits of P2,000 each into a bank account paying 8% interest per year. The first deposit will be made one year from today. How much money can be withdrawn from this bank account immediately after the 12th deposit?

a. 15.86%

c. P65,536

C5  P 200 ,00 (1  102 )5  P65,536

n

 1  P  F  1 i  = F(P/F, i%, n) P = P20,000(P/ F,9%,7) = P10,940.68

a. P35,492

b. P59,425

c. 17.86%

d. 18.86%

b.

strain

c. moment

d. torque

12.) A certain support stand design to carry downward loads. Compute the stress in the square shaft at the upper part of the stand for a load of 27,000 lb. The line of action of the applied of the applied load is centered on the axis on the shaft, and the load is applied through a thick plate that distributes the force to the entire cross section of the stand.

4

 0.15  ieff  1    1  15.86% 4   4.) A man purchased a house for P425,000. In the first month that he owned the house, he spent P75,000 on repairs and remodeling. Immediately after the house was remodeled, he was offered P545,000 to sell the house. After some consideration, he decided to keep the house and have it rented for P4,500 per month starting two months after the purchase. He collected rent for 15 months and then sold the house for P600,000. if the interest rate was 1.5% per month, how much extra money did he make or lose by not selling the house immediately after it was remodeled? a. P3,000

b.P4,000

c. P5,000

5.) On the day his grandson was born, a man deposited to a trust company a sufficient amount of money so that the boy could receive five annual payments of P20,000 each for his college tuition fees, starting with his 18th birthday. Interest at the rate of 12\$ per annum was to be paid on all amounts on deposit. There was also a provision that the grandson could elect to withdraw no annual payments and receive a single lump amount on his 25th birthday. The grandson chose this option. How much did the grandfather deposit? b. P10,500

c. P11,500

10,000psi



F 27,000lb lb   12,000 2  12,000 psi A 2.25in2 in

b. 11,000psi

c.

12,000psi

d. 13,000psi

13.) The proportional limit is the value of stress on the stress-strain diagram curve at which the curve first deviates from a straight line. a. b. c. d.

d. P6,000

Ans  P545 ,000  P 4,500 ( P / A,1.5%,15 )  P600 ,000 ( P / F ,1.5%,15 ) = P5,015

a. P9,500

a.

Proportional limit Elastic limit Yield point Tensile point

14.) It is the value of stress on the stress-strain curve at which the material has deformed plastically; that is, it will no longer return to its original size and shape after removing the load. a. b. c. d.

Proportional limit Elastic limit Yield point Tensile point

15.) It is the value of stress on the stress-strain curve at which there is a significant increase in strain with little or no increase in stress.

d. P12,500

a. b. c. d.

P  P 20 ,000 ( P / A,12 %,5)( P / F ,12 %,17 ) = P10 ,500

Proportional limit Elastic limit Yield point Tensile point

16.) It is the highest value of apparent stress on the stress-strain curve. 6.) A man bought an equipment costing P30,000 payable in 12 quarterly payments, each installment payable at the beginning of each period. The rate of interest is 24% compounded quarterly. What is the amount of each payment a. P1,700

b. P2,700

c.

P3,700

d. P4,700

7.) A telecommunication company purchased an equipment for P53,000 and paid P1,500 for freight and delivery charges to the job site. The equipment has a normal life of 10 years with a trade-in value of P5,000 against the purchase of a new equipment at the end of the life. Determine the annual depreciation cost by the sinking fund method. Assume interest at 6.5% compounded annually. b. P3,668

c. P4,215

CO  P53,000  P1,500  P54,500

Proportional limit Elastic limit Yield point Tensile point

17.) It is a measure of the stiffness of a material determined by the slope of the straight-line portion of the stress-strain curve.

P30 ,000  A(1  P / A,8%,12  1) A  P3,685 .96

a. P2,543

a. b. c. d.

d. P5,956

a. b. c. d.

Modulus of elasticity Modulus of rigidity Strain Stress

18.) A ductile material is one that can be stretched, formed, or drawn to a significant degree before fracture. A metal that exhibits a percent elongation greater than ____ % is considered to be ductile. a. 2

b.

3

c.

4

d. 5

CL  P5,000 d

P54,500  P5,000  P3,668 F / A,6.5%,10

1

19.) A brittle material is one that fails suddenly under load with little or no plastic deformation. A metal that exhibits a percent elongation ____ 5.0% is considered to be brittle.

Modulus of elasticity Modulus of rigidity Modulus of elongation Modulus of stressibility

a. 155.47psi



b. Brittleness

c. Hardness

d.

Toughness

22.) It is the indication of the resistance of a material to indentation by a penetrator. Ductility

b. Brittleness

c. Hardness

d.

Toughness

23.) It is a measure of pulling and pushing force. a. b. c. d.

c. 485MPa

d.

500MPa

b. 20MPa

c. 30MPa

b 

V ( 25 mm) 2 4

V  P  31.91kN



t

d.

40MPa

P dt P

P(3) (40mm) 2 300G  4 [(52mm) 2  (40mm) 2 ]150G

d b



T 

PL AE

c. 130MPa

d.

140MPa

 E

  TE  (11 .7  )(30  30 )( 200 G )   140 .4 MPa

PL AE

32.) A steel shaft 3ft long that has a diameter of 5in is subjected to a torque of 14kipft. Determine the maximum shearing stress. G=12x106 psi. a. 0.47°



b. 0.53°

c.

0.68°

d.

0.71°

TL 14k (12)(3x12) 180   ( 5) 4 x  0.47 6 JG  32 12 x10

a. 107.6mm

31.91kPa (25mm)130M t  9.82mm t

 4 x

113.3mm

c. 121.9mm

d. 126.4mm

TL JG

 180

13k (6)  ( d )4 32

85x109

34.) Determine the elongation in a helical steel spring composed of 20 turns of 20mm diameter wire on a mean radius of 90 mm when the spring is supporting a load of 2.5kN. Use G=83 GPa.

28.) A cylinder pressure vessel is fabricated from plates which have a thickness of 20mm. The diameter of the pressure vessel is 450 mm and its length is 3.5m. Determine the maximum internal pressure which can be applied if the stress in the steel is limited to 150MPa. c. 17.53MPa

b.

d  107.57mm

31 .91kNkN [125 mm  8mm  25 mm  8mm ]   39 .89 MPa



b. 16.67MPa

b. 120MPa

33.) What is the minimum diameter of a solid steel shaft that will not twist through more than 4° in a 6m length when subjected to a torque of 13kN-m? What max shearing stress is developed? G=85 GPa

P A

a. 15.33MPa

181kN

P ( 2 m) AE

   L T

 L T 

27.) Assume that a 25-mm diameter rivet joins the plates that are each 125 mm wide. The allowable stresses are 130 MPa for bearing in the plate material and 65 MPa for shearing of the rivet. Determine the minimum thickness of each plate.

65M 

d.

PL AE

a. 110MPa

b. 420MPa

V 2 4 d

c. 171kN

31.) A steel rod 3.5m long is secured between two walls. If the load on the rod is zero at 30°C, compute the stress when the temperature drops to -30°C. The cross sectional area of the rod is 1200mm2, α =11.7um/(m°C), and E=200GPa.

10,000N  500MPa 20 x106 m 2



b. 161kN

P  160.57kN

Axial force Shear force Torque Bending moments

a. 10MPa

30.) A steel bar 40mm in diameter and 3m long is surrounded by a shell of cast iron 6mm thick. Compute the load that will compress the combined bar a total of 0.95 mm in the length of 2m. For steel E=300GPa, and for cast iron, E=150GPa.

4

26.) A common bar suspended from certain support has axial load of 10kN. If the bar has a cross section of 20mm2, find the stress experience by the bar.



188.73psi

p(4  12in) 4(4 / 17in) p  176.47 psi

0.95  10 3 

25.) It is the measure of the resistance to twisting.

a. 350MPa

d.

pD 4t

0.8  10 3 m 

Axial force Shear force Torque Bending moments

c. 176.47psi

9000 



24.) It is the measure of the total resistance to sliding.

a. b. c. d.

b. 169.25psi

a. 151kN

Axial force Shear force Torque Bending moments

a. b. c. d.

2(25mm)

29.) The wall thickness of a 3ft-diameter spherical tank is 4/17 in. Calculate the allowable internal pressure if the stress is limited to 9000 psi.

21.) It is the ability of a material to absorbed applied energy without failure

a.

 (450mm)

  16.67MPa

20.) The ratio of shearing stress to shearing strain is called:

a. Ductility

2t

150MPa 

a. equal b. Greater than c. Less than d. It depends on the room temperature

a. b. c. d.

D

t 

a. 160mm



b. 165mm

c.

170mm

d.

175mm

3

64 (2.5k )( 90 mm ) ( 20 )  175 mm 83GPa ( 20 mm ) 4

d. 18.83MPa

2

35.) It is the transfer of energy from the more energetic particles of substance to the adjacent less energetic ones as a result of interactions between the particles. a. b.

c. Convection d. Absorption

a. 93.33%

36.) It indicates that the rate of heat conduction in a direction is proportional to the temperature gradient in that direction. a. b. c. d.

47.) A carnot heat engine receives 500KJ of heat per cycle from a high-temperature source at 600 °C and rejects heat a low temperature sink at 40°C. Determine the thermal efficiency of this Carnot engine.

Fourier’s Law of Heat Conduction Fourier’s Law of Heat Convection Fourier’s Law of Heat Radiation Fourier’s Law of Heat Absorption

  1

b. 6.67%

c. 35.85%

d. 64.15%

TL (40  273 ) K  1  0.6415 (64 .15 %) TH (600  273 ) K

48.) A piston cylinder device contains a liquid-vapor mixture of water at 400K. During a constant pressure process, 700 KJ of heat is transferred to the water. As a result, part of the liquid in the cylinder vaporizes. Determine the entropy change of the water during this process.

37.) Which of the following is considered the best conductor of heat? a. 1.75kJ/K a.

Gold

b. Copper

c. Silver

b.

280kJ-K

c. 7000kJ

d. 0.57K/kJ

d. Diamond

38.) It is the mode of energy transfer between a solid surface and the adjacent liquid or gas that is in motion, and it involves the combined effect conduction and fluid motion.

S 

Q 700kJ kJ   1.75 T 400K K

49.) Which of the following equation of state has two constants? a. b.

c. Convection d. Absorption

39.) It is the energy emitted by the matter in the form of electromagnetic waves as a result of the changes in the electronic configurations of the atom or molecules. a. b.

c. Convection d. Absorption

a. b. c. d.

50.) How many constant are there in Strobridge Equation of State? a.

40.) It states that energy can neither be destroyed nor created; it can only change forms. a. b. c. d.

First law of thermodynamics Second law of thermodynamics Third law of thermodynamics Zeroth law of thermodynamics

Kelvin –Plank Statement Clausius-Plank Statement Clausius Statement Kelvin Statement

a. b. c. d.

Kelvin –Plank Statement Clausius-Plank Statement Clausius Statement Kelvin Statement

Light intensity c. Light efficacy Light efficiency d. Light luminosity

1

b.

2

d. 16

Vander Waals Equation Beattie-Bridgeman Equation Benedict-Webb-Rubin Equation Strobridge Equation

120.5J/s

b. 135.7J/s

c. 143.2J/s

d. 151.9J/s

Qconvection  hA(Ts  T f ) W (1.2m 2 )(33  22)C m 2 C = 66W =5

= 0.95(5.67 x108

c.

3

W )(1.2m 2 )[(33  274) 4  (22  273) 4 ]K 4 m4  K 4

= 77.2W Qtotal  66W  77.2W  143.2W  143.2 J / s 53.) A piston cylinder device initially contains 0.8 m3 of air at 110kPa and 80°C. The air is now compressed to 0.2 m3 in such a way that the temperature inside the cylinder remains constant. Determine the work done during this process.

44.) Carnot cycle is composed of how many reversible processes? a.

c. 15

4 Qradiation   (Ts4  Tsurr )

43.) It is defined as the amount of light output in lumens per W of electricity consumed. a. b.

b. 14

52.) Consider a person standing in a breezy room at 22°C. Determine the total rate of heat transfer from this person if the exposed surface area and the average outer surface temperature of the person are 1.2 m2 and 33°C, respectively, and the convection heat transfer coefficient is 6 W/m2.ε=0.95 and σ=5.67x10-8 W/m4-K4 a.

42.) In second law of thermodynamic, which of the following state that no device can transfer heat from cooler body to a warmer one without leaving an effect on the surroundings.

13

51.) Which of the following equation of state has eight constant? a. b. c. d.

41.) In second law of thermodynamic, which of the following state that no heat engine can have a thermal efficiency of 100% or as far as power plant to operate, the working fluid must exchange heat with the environment as well as the furnace. a. b. c. d.

Vander Waals Equation Beattie-Bridgeman Equation Benedict-Webb-Rubin Equation Strobridge Equation

d. 4

a.

-122kJ

b. -123kJ

W  (110kPa)(0.8m 3 ) ln(

c. -124kJ

d. -125kJ

0.2 1kJ )( )  122kJ 0.8 1kPa  m 3

45.) Which of the following processes are involved in carnot cycle? a. b. c. d.

Two isothermal ; two isobaric One isothermal; three adiabatic Three isobaric; one adiabatic Two adiabatic ; two isothermal

54.) It is the energy possesses by the system as a result of its elevation with respect to the gravitational acceleration of the earth. a.

Potential b.Kinetic c. Momentum

d.Impulse

55.) It states that if two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. 46.) State that the thermal efficiencies of all reversible heat engines operating between the same two reservoirs are the same, and that no heat engine is more efficient than a reversible one operating between the same two reservoirs. a. b. c. d.

Throttle principle Otto principle Carnot principle Kelvin principle

a. b. c. d.

First law of thermodynamics Second law of thermodynamics Third law of thermodynamics Zeroth law of thermodynamics

3

56.) Determine the mass of the air in a room whose dimensions are (5x6x7) cm at 105 kPa and 27°C.

62.) A 4-in wall of fire brick, k=9 Btu/(ft2-hr-F/in), has one surface at 300F, the other at 90F. Find the heat conducted through the area of 2ft 2 in 1 day. a.

a.

Q  kAt

R'  gas constant R' air  0.287 m3 kPa / kg  K m

22, 680Btu

b. 19, 650Btu

d. 10,730Btu

105kPa(5 x6 x7m 3 ) PV   256.1g R' T 0.287 m3 kPa ( 27  273 K ) / kg  K

a.

48.91%

b. 51.09%

c. 32.84%

63.) If 80 g of iron shot at 100C is dropped into 200 g of water at 20C contained in an iron vessel of mass 50 g, find the resulting temperature. a.

20.1°C

b. 21.8°C

c. 22. 3°C

80(0.12)(T2  100)  200(1)(T2  20)  50(0.12)(T2  20) T2  24.6C 64.) When a 2lb of brass at 212°F is dropped into 5lb of water at 35°F, the resulting temperature is 41.2°F. Find the specific heat of brass in Btu/lb-°F. a.

QL  45 MJs QL 45 1  0.5109 (51.09%) QH 92

1.120

b. 0.091

c. 0.321

58.) The food compartment of a refrigerator is maintained at 4°C by removing heat from it at a rate of 300 KJ/min. If the required power input to the refrigerator is 3KW, determine the coefficient of performance of the refrigerator. b. 2.33

c. 3.67

d. 1.233

Qlost  Qgain Qbrass  Qwater 2lb(C )(212F  41.2 F )  5lb(1

1.67

d. 24.6°C

d. 67.15%

QH  92 MJs

 1

T Btu 300  90 F  (9 2 )(2 ft 2 )(24  hr ) in L 4 ft  hr  inF

= 22,680 Btu

57.) Heat is transferred to a heat engine from a furnace at a rate of 92MW. If the rate of waste heat rejection to a nearby river is 45MW, determine the net power output and the thermal efficiency for this heat engine.

a.

c. 15,510Btu

256.1 g

C  0.091

Btu )(41.2 F  35F ) lb  F

Btu lb  F

d. 4. 12 65.) How much heat is necessary to raise the temperature of 0.80 kg of ethyl alcohol from 15°C of its boiling point 78.3°C?

300kJ / min 1kW COP  ( )  1.67 3kW 60kJ / min

a.

10kcal b. 20kcal c. 30kcal d. 40kcal

Q  mct 59.) A 50 kg iron block at 80°C is dropped into an insulated tank that contains 0.5 m 3 of liquid water at 25°C. Determine the temperature when thermal equilibrium reached. The specific heat of iron is 0.45kJ/kg-°C and for water is 4.18kJ/kg-°C. a.

20. 7°C

b. 25.6°C

c. 30.1°C

50kg(0.45 kgkgC )(T2  80C ) 

d. 35.6°C

0.5m3 kJ )(T2  25C )  0 3 ( 4.18 kg  C 0.001 mkg

T2  25.6C

500kJ

cal )(78.3  15)C g  C

Q  30kcal 66.) The weight-density of air at 32F and 29.92 in Hg pressure is 0.081 lb/ft 3. What is its weight-density, in lb/ft3, at an altitude where the pressure is 13.73 in Hg and the temperature is -40F? a.

0.044

b. 0.055

c. 0.066

d. 0.77

 PV   PV       mT 1  mT  2

60.) A rigid tank contains a hot fluid that is cooled while being stirred by a paddle wheel. Initially, the internal energy of the fluid is 850kJ. During the cooling process, the fluid loses 550kJ of heat, and the paddle wheel does 200kJ of work on the fluid. Determine the final energy of the fluid. Neglect the energy stored in the paddle wheel. a.

Q  0.8kg(0.6

b. 550 kJ

c. 600kJ

d. 650 kJ

 P   P        T 1  T  2 29.92    13.73        0.081x 273K 1  x 233K  2 lb  2  0.044 3 ft

Q  U  W 200kJ  (U 2  850kJ )  550kJ U 2  500kJ

61.) Three moles of an ideal gas are compressed slowly and isothermally from a volume of 5 to 1.5 ft3, at a temperature of 320K. How much work is done? a.

-8.12kJ

W  nRT ln

b. -9.61kJ

c. -10.44kJ

d. -11.59kJ

V2 J 1. 5  3mol (8.317 )(320 K ) ln  9612 .9 J  9.61kJ V1 mol  K 5

4