Name: Period: POE Final Review

1

Name:_____________________________________________Period:____

POE Final Review

Procedure

Complete this review for your Principles of Engineering Final; refer back to previous handouts, notes and assignments. All the problems you see on this review may be on your final plus a surprise or two. Be sure to have a complete understanding of all of these problems and know where formulas are located on the formula sheet.

Refer back to your notes

Simple Machines – Lever

A first class lever, in static equilibrium, has a 48lb resistance force and 11.5 lb effort force. The lever’s effort force is located 5.5 ft from the fulcrum.

1. Sketch and annotate the lever system described above.

2. What is the actual mechanical advantage of the system?

Formula Substitute / Solve Final Answer

3. Using static equilibrium calculations, calculate the length from the fulcrum to the resistance force.


2

A wheel barrow is used to lift a 135 lb load. The length from the wheel axle to the center of the load is 1.8 ft. The length from the wheel and axle to the effort is 3.5ft.

4. Illustrate and annotate the lever system described above.

5. What is the ideal mechanical advantage of the system?


6. Using static equilibrium calculations, calculate the effort force needed to overcome the resistance force in the system.


Simple Machines – Wheel and Axle

7. What is the linear distance traveled in one revolution of a 65 in. diameter wheel?


An industrial water shutoff valve is designed to operate with 22 lb of effort force. The valve will encounter 195 lb of resistance force applied to a 1.625 in. diameter axle.

8. Sketch and annotate the wheel and axle system described above.

3

9. What is the required actual mechanical advantage of the system?


10. What is the required wheel diameter to overcome the resistance force?


Simple Machines – Pulley System

A construction crew lifts approximately 1880 lb of material several times during a day from a flatbed truck to a 59 ft rooftop. A block and tackle system with 621 lb of effort force is designed to lift the materials.

11. What is the required actual mechanical advantage?


12. How many supporting strands will be needed in the pulley system?


A block and tackle system with seven supporting strands is used to lift a metal lathe in a manufacturing facility. The motor being used to wind the cable in the pulley system can provide 125 lb of force.

13. What is the mechanical advantage of the system?


4

14. What is the maximum weight of the lathe?


Simple Machines – Inclined Plane

A civil engineer must design a wheelchair accessible ramp next to a set of steps leading up to a building. The height from the ground to the top of the stairs is 5 ft. Based on ADA codes, the slope must be 1:12 or less. Slope is equal to the rise of the ramp divided by the run of the ramp.

15. Sketch and annotate the inclined plane described above.

16. Using the ADA code, what is the allowable minimum length of the ramp base?


17. Using the known height and calculated base length, what is the length of the slope

of the ramp?


18. What is the ideal mechanical advantage of the ramp?


5

19. If a person and wheelchair have a combined weight of 325 lb, how much ideal effort

force is required to travel up the ramp?


20. For each of the resistors shown below, use Ohm’s law to calculate the unknown

quantity. Be sure to put your answer in proper engineering notation and use the correct units.

21. For each of the circuits shown below, calculate the value for RT. Be sure to put your answer in proper engineering notation and use the correct units.

6

22. Using the laws of circuit theory, solve for RT, IT, VR1, VR2, and VR3. Be sure to put your answer in proper engineering notation and use the correct units.

Gears

A simple gear train is composed of three gears. Gear A is the driver and has 8 teeth, gear B has 25 teeth, and gear C has 42 teeth.

23. Sketch and annotate the gear train described above.

24. If the output is at C, what is the gear ratio?


7

25. If gear A rotates at 35 rpm, how fast is gear C rotating?


26. If the output of torque at gear C is 220 ft·lb, what is the input torque at gear A?


Pulleys and Belts

In a pulley system, pulley A is moving at 9800 rpm and has a diameter of 13 in. Three pulleys, B, C, and D, all of different sizes, are attached to a single output axle. Speed and torque output are changed within the system by moving the drive belt between pulleys B, C, and D.

27. Sketch and annotate the drive train described above.

28. A speed of 3850 rpm is required when the drive belt is connected to pulley B. What

is the diameter of pulley B?


8

29. A speed of 2900 rpm is required when the drive belt is connected to pulley C. What is the diameter of pulley C?


30. A speed of 3200 rpm is required when the drive belt is connected to pulley D. What

is the diameter of pulley D?


31. Label the annotation for reading thread

notes.

9

Thermodynamics Directions: Carefully read each story problem and solve. 32. A 6 kg piece of aluminum metal at 95°C is placed in 5 liters (=5kg of water at 45°C.

Determine the final temperature (Tf).

List known values:

Cp-Al = 900

Cp-water = 4184

List unknown values:

List Equations: Apply known values:

Solve

33. A traveler rides on a train in the middle of winter from the train station to work. The

train temperature is 72° F. The traveler’s skin temperature is 97.5° F. Determine the net energy transfer from the travelers body during the 52 min ride to work due to electromagnetic radiation. Note: Skin emissivity is 0.90, and the surface area of the student is 1.50m2.

List known values:

ϭ = 5.6696 x 10-8 w/ m2 k 4

List unknown values:

List Equations:

K = 5/9 (° F - 32) + 273

Apply known values:

Solve

10

34. A ¼” thick acrylic testing box with dimensions 12” x 12” is covered with an unknown ¼” insulation material. Determine the thermal conductivity for the insulating material if a 60W bulb is used to heat the box. The bulb maintains the inside temperature at 22ºC higher than the outside temperature.

List known values: List unknown values:

List Equations:

1 inches = 0.0254 meters

Apply known values:

Solve

Projectile Motion Directions: Carefully read each story problem and solve. Show all of you work be sure to use the proper equations and label your answers. 35. A fishing bobber is casted at a 32 degree angle with an initial velocity of 19 ft per

second. How far will the cast travel before hitting the water?

12”x12” test box

11

36. A bullet lands 0.48 of a mile from the barrel of the muzzle with a velocity of 650 feet

per second. What was the angle the bullet was shot at?

37. A golf ball travels 175 yards at angle off the tee of 25 degrees, what is the speed at

the club head?

38. A ballistic device launches a ballistic 9000 feet with a velocity of 175 feet per

second. What angle was the ballistic shot at?

39. A baseball is hit at a 37 degree angle with an initial velocity of 37 feet per second,

how far will the ball travel before it lands?

40. A missile is launched 200 miles shot at a 35 degree angle, what is the speed of the

missile?

Fluid Power Directions: Read each practice problem carefully and solve for the missing values, be sure to show all of your work. Charles’s Law 41. An expandable container is filled with 45 in.3 of air and is sitting in ice water that is

33°F. The container is removed from the icy water and is heated to 250.°F. What is the resulting volume?

V1 = ____in.3 V2 = ? T1 = ____°F T2 = ____°F

1 2

1 2

V VFormula

T T

12

Convert T to absolute temperature. T1 = ____°F + 460.°F = ____°R T2 = ____°F + 460.°F = ____°R

V2 = _____________ in.3 42. The same size container is filled with 50 in.3of air and is now sitting at room

temperature (71 °F). The container is then moved from room temperature room to a new room with an unknown temp. The volume then condenses to 45 in.3. Calculate what the second room’s temperature.

V1 = ____in.3 V2 =____in.3 T1 = ____°F Substitute and Solve: T2 = ?

T2 = ________________°F Boyle’s Law

44.) A cylinder is filled with 75. in3

of air at a pressure of 45. psi. The cylinder is

compressed to 26. in3

. What is the resulting absolute pressure?

p1 = _______ lb/in.

2

V1 = ______ in.

3

Substitute/Solve

p2 = ? V

2 = ______in.

3

Convert p1 to absolute pressure.

p1 = _______lb/in.

2

+ 14.7 lb/in.2

= ______lb/in.2

p2 = _______lb/in.

2

+ 14.7 lb/in.2

= ______lb/in.2

p2 = ___________lb/in.

2

1 2

1 2

V VFormula

T T

1 1 2 2Formula (V ) (V )p p

13

45.) A cylinder is filled with 52 in.3

of air at a pressure of 27. psi. The cylinder is compressed to an unknown volume. If the resulting absolute pressure is 175psi, what was the volume that the cylinder was compressed to?

p1 = _______ lb/in.

2

V1 = ______ in.

3

p2 = _______ lb/in.

2

V2 = ?

Substitute/Solve

Convert p1 to absolute pressure.

p1 = _______lb/in.

2

+ 14.7 lb/in.2

= ______lb/in.2

V2 = ______in.

3

Gay-Lussac’s Law 46.) A 250. in.3 sealed air tank is sitting in a train car in transport to its final destination. In the train car the temperature inside the tank is 92°F, and the pressure gauge reads 160. lb/in.2. By the time it is moved from the train car to the freight truck, the temperature inside the tank is expected to be close to 102.°F. What will the absolute pressure be at that point? V = _____ in.3 T1 = _____°F p1 = _____lb/in.2 T2 = _____°F p2 = ? Substitute and Solve Convert p to absolute pressure. p1= ______ lb/in.2 + 14.7 lb/in.2 = ______ lb/in.2 Convert T to absolute temperature. T1 = ______°F + 460.°F = ______°R T2 = ______°F + 460.°F = ______°R p2 = __________________ lb/in.2

1 1 2 2Formula (V ) (V )p p

p p1 2

1 2

FormulaT T

14

47.) The same container transport train was carrying another sealed air tank; this tank had a temperature in the train of 82°F and a volume A 450. in.3 The pressure gauge reads 160. lb/in.2. This container is moved onto a different truck for transport and the temperature reaches an unsafe high. The pressure gage read 250 psi, which is far to high for the container, and the container blows and starts leaking. Once the container reached its destination it is totally destroyed. To prevent this from happening again the workers want to determine what the Absolute and regular temperature of the truck was during transport. V = _____ in. T1 = _____°F p1 = _____lb/in.2 T2 = ? p2 = _____lb/in.2 Substitute and Solve Convert p to absolute pressure. p1= _____ lb/in.2 + 14.7 lb/in.2 = _____ lb/in.2

p2= _____ lb/in.2 + 14.7 lb/in.2 = _____ lb/in.2 Convert T to absolute temperature. T1 = ______°F + 460.°F = _____°R T2 = ______°R - 460.°F = _____°F T2 = ______________°R T2 = ______________°F

48.) What is the definition of pneumatics?

49.) What is the definition of hydraulics?

50.) What is the difference between the two?

p p1 2

1 2

FormulaT T

15

3.7 in 2

2.3 in 2

51.) List 4 practical applications that you would see the use of pneumatics in?

a.

b.

c.

d.

52.) List 4 practical applications that you see the use of hydraulics in?

e.

f.

g.

h.

53. What does Pascal’s Law State?

Directions: Solve the practice fluid systems problems below. (2 points each)

54. If a 750 lb force is applied to the top of cylinder 1’s rod, how much Fluid pressure will be

generated in the system?

Input 550 lbs force

Output force

Answer: ___________psi

Piston 1

Piston 2

P= F/A P= Pressure F= Force A= Area

16

13 in 2

4.7 in 2

55. How much force will be generated at piston 2?

56. If a 1234 lb force is applied to the top of cylinder 1’s rod, how much Fluid pressure will be generated in the system?

57. How much force will be generated at piston 2?

Answer: ____________lbs

Input 1234 lbs force

Output force


Answer: ____________lbs

Piston 1 Piston 2

17

11 in 2 3 in 2

58. If 3456 lbs of force is generated at the top of cylinder 2’s rod, how much psi will be

necessary to operate this system?

59. How much force will need to be applied at piston 1?

Input force Output 3456 lbs force


Answer: ____________lbs

Piston 1 Piston 2

18

60. A garden hose is used to fill a 35 gallon water trough in 12 minutes, what is the flow rate

of the garden hose?

Q= flow rate V= volume t= time

61. A garden hose is used to fill an outdoor 66,300 gallon pond With a flow rate of 3 gpm,

how long will it take to fill the pond?

62. An oil tanker can fill a gas station tank that is 6700 gallons in 18 minutes, what is the

flow rate of the tanker truck?

Answer: ____________gpm

Q= v/t

Answer: ____________gpm

Answer: ___________ mins Answer: ____________hrs Answer: __________days

19

Beam Deflection

63.) Complete the chart below by calculating the cross-sectional area, Moment of Inertia, and beam deflection, given a load of 350 lbf, a Modulus of Elasticity of 1,345,000 psi, and a span of 12 ft. Show all work in your engineering notebook.

Beam A B C D E F

Common Name

2x6 2x6 2x8 2x8 2x10 2x10

Actual Dimensions

(in.) 1.5 x 5.5 1.5 x 5.5 1.5 x 7.25 1.5 x 7.25 1.5 x 9.25 1.5 x 9.25

Vertical or Horizontal Orientation

Cross-Sectional Area (in.2)

Moment of Inertia (in.4)

Beam Deflection

(in.)

20

Centroids

64.) Solve for the missing information


21



22

Materials testing 68.) A solid circular titanium control rod at 5,000 lb axial tension force, stress must not exceed 52,000 psi. Assume that the modulus of elasticity of the titanium is 16,500,000 psi and that the rod must elongate no more than 0.18 in. Determine (a) the minimum rod diameter (precision 0.00) and (b) the maximum rod length. (precision of 1)

69.) A 1.25 in. by 3 in. rectangular steel bar is used as a diagonal tension member in a bridge truss. The diagonal member is 20 ft long, and its modulus of elasticity is 30,000,000 psi. If the strain in the diagonal member is measured as 0.001200 in./in., determine:

a. The axial stress (precision of 1,000)

b. The tension force in the bar (precision of 10,000)

c. The elongation of the member (precision of 0.00)

23

Truss Problem 70.) Be sure to show all work (This will be the only way I can award partial credit) and put all final answers on the below truss system. Do not forget to label each force as compression (C) or tension (T). Each square equals 1 meter. You may use the step-by-step truss sheet on this quiz.

Name: Period: POE Final Review

Documents

Transcript of Name: Period: POE Final Review