midterm study guide

Concepts of Engineering Midterm Study Guide for Semester 2

Due 3/13/15

Directions:  Technical Tier 1 students may simply download this form, save it, and type the information from the flashcards http://www.quizmeonline.net/flashcards/Study-Guide-for-Foundations-of-Engineering-Midterm-2nd-Semester

Technical Tier 2 students will put the questions and answers to this information (see the web link above) on their blog and send me their blog post link via Edmodo.

Technical Tier 3 students will record this information (see the web link above) using Powerpoint slides and a screencast or vocaroo.com and send me the links via Edmodo.  (This level has to be done on your home computer) 

The basic point value is 100 points, but an extra 50 bonus points will be given for tier 2 and 100 bonus points will be given for Tier 3 entries. 

Questions

1.       Advantages of Pneumatics over Hydraulics– (write/type the 5 key things from the flashcards here)

Advantages of Pneumatics over Hydraulics

Hydraulics present certain advantages over pneumatics, but in a given application, pneumatic powered equipment is more suitable, particularly in industries where the factory units are plumbed for _____________ air. COMPRESSED.

In order to affect ______ motion, pneumatics employs compression of gases, based on the working principles of fluid dynamics in the concept of pressure. MECHANICAL.

Any equipment employing pneumatics uses an ________ set of components: a pneumatic circuit consisting of active components such as gas compressor, transition lines, air tanks, hoses, open atmosphere, and passive components.

Interconnecting.

Hydraulics means use of __________ fluids to execute a mechanical task.

pressurized

Commonly seen _________ based equipment types are hydraulic presses, hydraulic hoppers, hydraulic cylinders, and hydraulic rams.

hydraulics

2.       Chapter 18 -  (write/type 3 key things from the flashcards here)

Which technologies apply the concepts of Newton's third law? jet airplanes, fireworks, and recoil guns.

What is Newton's Third Law? Use it to explain how a rocket engine propels a spacecraft into outer space.

Every action has an equal and opposite reaction. Thrusters will propel the spacecraft into outer space by pushing hot gases out a very high velocity. According to Newton's third law, the spacecraft will experience an equal and opposite force, propelling it upward into space. Also, acceleration of the games times their mass equals the acceleration of the rocket times its mass.

What is meant by the term "resistance"?

Resistance opposes forward movement.

What does ETF stand for?

Engineering the Future

Other engineers have tackled the problem of making more efficient cars. What are some new car technologies in development today that are designed to reduce the use of fossil fuels?

Hybrid vehicles have both gas engines, and electric motors and batteries, so they can use both energy sources, either one at a time or together. Hybrid vehicles capture energy from braking to generate electricity and charge the batteries. Solar - powered vehicles use photovoltaic (solar) cells; hydrogen-powered vehicles are reenergized with hydrogen gas, or are powered by fuel cells.

3.       Chapter 19 -  (write/type 5 key things from the flashcards here)

what is the difference between a gas engine and diesel engine? The main difference between the two types of engines is in the way that they ignite the gas-air mixture. Gasoline engines take in a mixture of gas and air, compress it, and then ignite it with a spark plug. Diesel engines take in just air, compress it, and then inject fuel into the compressed air. The air is compressed enough to raise its temperature sufficiently so that the injected fuel will ignite it.

Give both an advantage and a disadvantage of a diesel engine over a gasoline engine. Diesel engines are more powerful, and therefore are used to power trains, cargo ships, and other heavy vehicles. Diesel engine exhaust contains more soot and other particulate pollutants than gasoline engines.

What information would you need to know to determine the force with which the piston pushes the air during the second step of the diesel cycle? P=F/A, therefore F= A x P. You would need to determine the pressure in the chamber and the surface area of the piston.

What is the relationship between volume, temperature, and pressure that is useful for designing engines?

Volume, temperature, and pressure are related by the equation "Pressure (P) is proportional to the temperature (T) of the gas, divided by the volume (V) of the chamber.

What were the design requirements for the wheelchair engine? Why did the Stirling engine seem like it might meet the criteria?

The engine had to be quiet and had to deliver a lot of power. Because the Stirling engine is an external combustion engine, there are no explosions inside of the combustion chamber. Therefore, the engine is very quiet.

"

4.        Chapter 20 (write/type 5 key things from the flashcards here)

According to an article in a financial journal, a certain company earned 3.85 million dollars last year. Based on this report of the company's yearly earnings, a person reading the article estimates that the company earned an average of approximately 30 thousand dollars per month. Which of the following statements best describes the reasonableness of this estimate for the company's average monthly earnings?
A. The estimate is too low by a factor of 100.
B. The estimate is too low by a factor of 10.
C. The estimate is too high by a factor of 10.
D. The estimate is too high by a factor of 100.

Correct Response B: One way to solve this problem is to divide 3.85 million dollars by 12 months. Write 3.85 million as 3,850,000. Since the number of dollars will be divided by 12 and the question is asking for an estimate, use compatible numbers to estimate 3,850,000 as 3,600,000, which divides evenly by 12: 3,600,000 dollars divided by 12 months equals 300,000 dollars per month. Hence, 30 thousand dollars per month is too low by a factor of 10. Another way to solve this problem is using multiplication. If the company made $30 thousand per month and there are 12 months in the year, then it is possible to evaluate the person's estimate by finding the product of 12 and 30 thousand dollars to get 12 × $30 thousand = $360 thousand = $360,000.

What effect do sleep debts have on the brain? Some say these sleep debts can have a powerful effect on a teen's ability to learn and retain new material -- especially abstract concepts like physics, math, and calculus.

In the number 2010, the value represented by the digit 1 is what fraction of the value represented by the digit 2?
A. 1/2000
B. 1/200
C. 1/20
D. 1/2 -

Correct Response B: In a place value system, the value of a digit depends on the position it occupies. For the number 2010, the value of the position of each digit is shown below.
thousands = 2
hundreds = 0
tens = 1
ones = 0 -

What is Edmodo?

Edmodo is a social networking website and learning management system for teachers, students, and parents. It is marketed as the Facebook for schools -

What is meant by the term "resistance"?

Resistance opposes forward movement.

Math – Questions – These questions help you demonstrate your logic and though processing skills.  They are essential to understand in engineering.

Study the questions from the flashcards as well as these below .  Please note that the answers on the actual midterm will not be in the same order, so don’t think about memorizing the answer.  You need to understand the process, so make sure that you read the explanation given. 

Correct Response B: It is given in the question that the numbers in the diagram are rounded to the nearest whole number. Let w represent the length of the smallest side of the rectangle and l represent the length of the longest side of the rectangle. Because of the rules of rounding, the smallest possible value of w is 1.5 in. Note that if w were smaller, say 1.49 in., then it would have been rounded down to 1 in. The same line of reasoning applied to l indicates that the smallest possible value of l is 3.5 in. Since the area of a rectangle A is given by A = l × w, the smallest possible value for the actual area of the given rectangle is A = (1.5 in.)(3.5 in.) = 5.25 square inches. The largest possible value of w is 2.49 in. to two decimal places, 2.499 in. to three decimal places, 2.4999 in. to four decimals places, etc. Likewise, the largest possible value of l is 4.49 in. to two decimal places, 4.499 in. to three decimal places, 4.4999 in. to four decimal places. Since these values are very close to, but less than 2.5 in. and 4.5 in., respectively, we can conclude that the area of the rectangle must always be less than (2.5 in.)(4.5 in) = 11.25 square inches. Therefore, the area of the rectangle must be greater than or equal to 5.25 square inches and less than 11.25 square inches (5.25 ≤ A < 11.25). Of the answer choices given, only 5.5 square inches is in this range.

Incorrect Response A: This response comes from correctly noting that the smallest possible value for the side lengths are w = 1.5 in. and l = 3.5 in., but by finding the sum of l and w instead of the product of l and w. The sum of l and w is not the area of the rectangle. The sum would be 5.0 inches, not 5.0 square inches.

Incorrect Response C: This response most likely results from incorrectly calculating the largest possible area of the rectangle, as described above. Incorrect Response D: This response comes from using the values given in the diagram, and then finding the perimeter of (i.e., the distance around) the rectangle, instead of the area of the rectangle. The perimeter would be 12.0 inches, not 12.0 square inches.

Incorrect Response D: This response comes from using the values given in the diagram, and then finding the perimeter of (i.e., the distance around) the rectangle, instead of the area of the rectangle. The perimeter would be 12.0 inches, not 12.0 square inches.

Concepts of Engineering Midterm Study Guide for Semester 2

Due 3/13/15

Directions:  Technical Tier 1 students may simply download this form, save it, and type the information from the flashcards http://www.quizmeonline.net/flashcards/Study-Guide-for-Foundations-of-Engineering-Midterm-2nd-Semester

Technical Tier 2 students will put the questions and answers to this information (see the web link above) on their blog and send me their blog post link via Edmodo.

Technical Tier 3 students will record this information (see the web link above) using Powerpoint slides and a screencast or vocaroo.com and send me the links via Edmodo.  (This level has to be done on your home computer) 

The basic point value is 100 points, but an extra 50 bonus points will be given for tier 2 and 100 bonus points will be given for Tier 3 entries. 

Questions

1.       Advantages of Pneumatics over Hydraulics– (write/type the 5 key things from the flashcards here)

Advantages of Pneumatics over Hydraulics

Hydraulics present certain advantages over pneumatics, but in a given application, pneumatic powered equipment is more suitable, particularly in industries where the factory units are plumbed for _____________ air. COMPRESSED.

In order to affect ______ motion, pneumatics employs compression of gases, based on the working principles of fluid dynamics in the concept of pressure. MECHANICAL.

Any equipment employing pneumatics uses an ________ set of components: a pneumatic circuit consisting of active components such as gas compressor, transition lines, air tanks, hoses, open atmosphere, and passive components.

Interconnecting.

Hydraulics means use of __________ fluids to execute a mechanical task.

pressurized

Commonly seen _________ based equipment types are hydraulic presses, hydraulic hoppers, hydraulic cylinders, and hydraulic rams.

hydraulics

2.       Chapter 18 -  (write/type 3 key things from the flashcards here)

Which technologies apply the concepts of Newton's third law? jet airplanes, fireworks, and recoil guns.

What is Newton's Third Law? Use it to explain how a rocket engine propels a spacecraft into outer space.

Every action has an equal and opposite reaction. Thrusters will propel the spacecraft into outer space by pushing hot gases out a very high velocity. According to Newton's third law, the spacecraft will experience an equal and opposite force, propelling it upward into space. Also, acceleration of the games times their mass equals the acceleration of the rocket times its mass.

What is meant by the term "resistance"?

Resistance opposes forward movement.

What does ETF stand for?

Engineering the Future

Other engineers have tackled the problem of making more efficient cars. What are some new car technologies in development today that are designed to reduce the use of fossil fuels?

Hybrid vehicles have both gas engines, and electric motors and batteries, so they can use both energy sources, either one at a time or together. Hybrid vehicles capture energy from braking to generate electricity and charge the batteries. Solar - powered vehicles use photovoltaic (solar) cells; hydrogen-powered vehicles are reenergized with hydrogen gas, or are powered by fuel cells.

3.       Chapter 19 -  (write/type 5 key things from the flashcards here)

what is the difference between a gas engine and diesel engine? The main difference between the two types of engines is in the way that they ignite the gas-air mixture. Gasoline engines take in a mixture of gas and air, compress it, and then ignite it with a spark plug. Diesel engines take in just air, compress it, and then inject fuel into the compressed air. The air is compressed enough to raise its temperature sufficiently so that the injected fuel will ignite it.

Give both an advantage and a disadvantage of a diesel engine over a gasoline engine. Diesel engines are more powerful, and therefore are used to power trains, cargo ships, and other heavy vehicles. Diesel engine exhaust contains more soot and other particulate pollutants than gasoline engines.

What information would you need to know to determine the force with which the piston pushes the air during the second step of the diesel cycle? P=F/A, therefore F= A x P. You would need to determine the pressure in the chamber and the surface area of the piston.

What is the relationship between volume, temperature, and pressure that is useful for designing engines?

Volume, temperature, and pressure are related by the equation "Pressure (P) is proportional to the temperature (T) of the gas, divided by the volume (V) of the chamber.

What were the design requirements for the wheelchair engine? Why did the Stirling engine seem like it might meet the criteria?

The engine had to be quiet and had to deliver a lot of power. Because the Stirling engine is an external combustion engine, there are no explosions inside of the combustion chamber. Therefore, the engine is very quiet.

"

4.        Chapter 20 (write/type 5 key things from the flashcards here)

According to an article in a financial journal, a certain company earned 3.85 million dollars last year. Based on this report of the company's yearly earnings, a person reading the article estimates that the company earned an average of approximately 30 thousand dollars per month. Which of the following statements best describes the reasonableness of this estimate for the company's average monthly earnings?
A. The estimate is too low by a factor of 100.
B. The estimate is too low by a factor of 10.
C. The estimate is too high by a factor of 10.
D. The estimate is too high by a factor of 100.

Correct Response B: One way to solve this problem is to divide 3.85 million dollars by 12 months. Write 3.85 million as 3,850,000. Since the number of dollars will be divided by 12 and the question is asking for an estimate, use compatible numbers to estimate 3,850,000 as 3,600,000, which divides evenly by 12: 3,600,000 dollars divided by 12 months equals 300,000 dollars per month. Hence, 30 thousand dollars per month is too low by a factor of 10. Another way to solve this problem is using multiplication. If the company made $30 thousand per month and there are 12 months in the year, then it is possible to evaluate the person's estimate by finding the product of 12 and 30 thousand dollars to get 12 × $30 thousand = $360 thousand = $360,000.

What effect do sleep debts have on the brain? Some say these sleep debts can have a powerful effect on a teen's ability to learn and retain new material -- especially abstract concepts like physics, math, and calculus.

In the number 2010, the value represented by the digit 1 is what fraction of the value represented by the digit 2?
A. 1/2000
B. 1/200
C. 1/20
D. 1/2 -

Correct Response B: In a place value system, the value of a digit depends on the position it occupies. For the number 2010, the value of the position of each digit is shown below.
thousands = 2
hundreds = 0
tens = 1
ones = 0 -

What is Edmodo?

Edmodo is a social networking website and learning management system for teachers, students, and parents. It is marketed as the Facebook for schools -

What is meant by the term "resistance"?

Resistance opposes forward movement.

Math – Questions – These questions help you demonstrate your logic and though processing skills.  They are essential to understand in engineering.

Study the questions from the flashcards as well as these below .  Please note that the answers on the actual midterm will not be in the same order, so don’t think about memorizing the answer.  You need to understand the process, so make sure that you read the explanation given. 

Correct Response B: It is given in the question that the numbers in the diagram are rounded to the nearest whole number. Let w represent the length of the smallest side of the rectangle and l represent the length of the longest side of the rectangle. Because of the rules of rounding, the smallest possible value of w is 1.5 in. Note that if w were smaller, say 1.49 in., then it would have been rounded down to 1 in. The same line of reasoning applied to l indicates that the smallest possible value of l is 3.5 in. Since the area of a rectangle A is given by A = l × w, the smallest possible value for the actual area of the given rectangle is A = (1.5 in.)(3.5 in.) = 5.25 square inches. The largest possible value of w is 2.49 in. to two decimal places, 2.499 in. to three decimal places, 2.4999 in. to four decimals places, etc. Likewise, the largest possible value of l is 4.49 in. to two decimal places, 4.499 in. to three decimal places, 4.4999 in. to four decimal places. Since these values are very close to, but less than 2.5 in. and 4.5 in., respectively, we can conclude that the area of the rectangle must always be less than (2.5 in.)(4.5 in) = 11.25 square inches. Therefore, the area of the rectangle must be greater than or equal to 5.25 square inches and less than 11.25 square inches (5.25 ≤ A < 11.25). Of the answer choices given, only 5.5 square inches is in this range.

Incorrect Response A: This response comes from correctly noting that the smallest possible value for the side lengths are w = 1.5 in. and l = 3.5 in., but by finding the sum of l and w instead of the product of l and w. The sum of l and w is not the area of the rectangle. The sum would be 5.0 inches, not 5.0 square inches.

Incorrect Response C: This response most likely results from incorrectly calculating the largest possible area of the rectangle, as described above. Incorrect Response D: This response comes from using the values given in the diagram, and then finding the perimeter of (i.e., the distance around) the rectangle, instead of the area of the rectangle. The perimeter would be 12.0 inches, not 12.0 square inches.

Incorrect Response D: This response comes from using the values given in the diagram, and then finding the perimeter of (i.e., the distance around) the rectangle, instead of the area of the rectangle. The perimeter would be 12.0 inches, not 12.0 square inches.