The Deep Dive

This week during Lecture, Mrs. Vestal showed us the first two segments of the 1999 news report on IDEO's engineering design process. We watched the team rise to the challenge of researching, brainstorming, designing, and testing an upgraded shopping cart that addresses four main needs: safety, shopping, checkout and finding what you need.

While watching the diverse group brainstorm and test their ideas, I really wanted to join them! IDEO's environment and culture is conducive to entrepreneurship and improvement. I hope to see more businesses employing the use of IDEO's methods into their workspaces as I become part of the workforce.

The three segments of the program can be found here:
Part 1 The Deep Dive
Part 2 The Deep Dive
Part 3 The Deep Dive

Notes-2 from Chapter 8, Thinking Like an Engineer

1. The Six Types of Energy and the Units used

   Type of Energy	Units	Explanation
   Work (W)	W = Fd	-Energy used by exerting a force (F) over a distance (d) -Measured in joules (J)  J = Nm      (1 Newton meter) -Alternative measurement: ft (lb_force)
   Potential Energy (PE)	PE = mgh	-type of work -moving a weight (force; mass times gravity) a vertical distance (height; h)
   Kinetic Energy (KE)	KE_translational = 1/2mv^2 KE_rotational = ½ I w^2 Total KE = KE_t + KE_r	-characteristic of an object in motion -KE translational: If a constant force is applied to an object then the object’s acceleration will remain constant as proven by F=ma and the object’s velocity will increase in consistent intervals -KE rotational: Rotating objects also have kinetic energy whether they move along a distance or not. EX) Bicycle wheel- when in motion it does not move a distance but it does rotate It is calculated using angular velocity (Greek letter omega; w) which is the object’s rotational speech given in units of radians per second and the moment of inertia (I) which depends on mass and geometry of object -Total KE equals KE translational and KE rotational values
   Thermal Energy	Q = mCT	-Heat (Q) -Thermal energy is associated with a change in temperature (T), the mass of an object (m) and the specific heat of the object (C). -Can be expressed in British thermal units (BTUs) and calories BTU:  “amount of heat required to raise the temperature of one pound-mass of water by one degree Fahrenheit” Calorie: “amount of heat required to raise the temperature of one gram of water by one degree Celsius”

2. Power

   Power (W)

   W = J/s

   -Power (watts; W) is described as energy (joules; J) per time (seconds; s) -Power is a rate -Alternative measurement: horsepower (hp); described as the power used to replace the work that can be completed by a horse EX) Running a mile in 5 minutes versus running a mile in 10 minutes Running a mile in 5 minutes will require you to produce energy in a smaller amount of time (comparatively more power is generated) Running a mile in 10 minutes will require you to produce the same amount of energy in a longer amount of time (comparatively less power is generated)
3. Electric Concepts (electric charge, electric current, voltage, electric resistance, electric power)
   
   
   

   Electrical Concept	Units	Explanation
   Electric Charge Symbol: (Q)	C = As	-In basic terms, electric charge is measured by the charge “e”      Proton e = +1      Electron e = -1 -More generally, electric charge in measured in coulombs (C)      C = Amperes * time in seconds      1 coulomb = the total      charge of 6.24 x 10^18      protons -Subatomic particles experience repulsive (like-charge) and attractive (opposite charge) forces as described by Coulomb’s Law which is a function of the charge of two objects and the distance between the charges (r)  -K_e is coulomb’s constant 9 x 10^9 N m^2 / C^2
   Electric Current Symbol: I	A = C/s	-movement of charges in a solid material -it is assumed that charges move from the negative terminal to the positive terminal -measured in amperes (A), which represent the movement of one coulomb (C) of charge past any given point per second (s) -circuit diagrams denote the direction of the charges
   Voltage Symbol: V	V = J/C	-a measure that quantifies the work required to move an electric charge in the vicinity of other electric charges -measured in volts (V) which equals 1 joule/ 1 coulomb or the energy required to move a coulomb of charge one place to another. The voltage between these two places in one volt.      W = Fd      W = QV -PE in voltage is evident when charges are surrounded by like charges -KE in voltage is evident when charges are surrounded by opposite charges -need to note assumed polarity of a voltage (which end of device is more positive); used to track whether energy is being stored or released
   Electrical Resistance Symbol: R	M = V/A	-measures how difficult it is to move charges through a material -measured in ohms (Greek letter omega; symbol won't show up so for our purposes the symbol is M) which is defined as one volt (V) per ampere (A) In other words, if a 1 volt battery was connected to a device having a resistance of one ohm, then one ampere of current would flow through the device. “Resistance relates the voltage across a device to the current through the device.” -Electric current travels through a substance -The voltage is the difference between the forces exerted on a charge from both ends of a device depending on the charge of each end of the device -related to current and voltage by Ohm’s Law -To maintain a constant current through a resistance requires a voltage proportional to the resistance -Current is inversely proportional to resistance. If voltage increases, current increases. If resistance increases, current decreases because the voltage has a harder time pushing the charges through the device.
   Electric Power Symbol: P	P = VI                (V=voltage) P = VA                  (V=volts) P = (J/C)*(C/s) P = J/s	-Measures energy released and stored in electrical charges due to voltage and current -Electrical power is a function of the work required to move an electrical charge in the vicinity of other charges (voltage; V) and the movement of charges in a solid material (amperes; A) -Electrical power is a rate

   
   
4. Discuss resistors
   
   
   Resistor: An object that has resistance to electrical current
   The electrical power that is stored in a resistor due to charges being near like charges is usually converted to heat.
   Equations that are used to solve for the amount of power absorbed by a resistor:
   P = VI = (IR) I = I^2R
   P = VI = V(V/R) = V^2/R
   Specifications: resistance and wattage
   
   
5. Discuss capacitors
   
   
   Formed by putting two conducting, low resistance plates close to one another, each with a wire connected to it, and separating them with an insulator that has extreme resistance
   When a current made of electrons is run through one of the two plates, electrons begin to build up on that plate because they cannot penetrate through the insulator material. The build up of electrons repels the negative charges on the opposite plate, which leaves an overall positive charge on the opposite plate. This gives the impression that the current has traveled through the insulator, but it hasn't. The charge stored in a capacitor is proportional to the voltage across it: Q = CV  
   C is a proportionality constant
   Referred to as capacitance (C)

   Measured in farads (F)

   units of F: coulombs per volt

   F = C/V

   If a capacitor stores a charge of one coulomb and the resulting voltage is one volt, then the capacitance is one farad. 

   
   The energy stored in a capacitor: E = 1/2CV^2 (formula similar to kinetic energy)
   Specifications: capacitance and maximum voltage
   
   6. Inductors
   
   Generally an inductor is simply a coil or wire
   If a current is run through a wire, it generates a magnetic field.
   If a wire is in an environment with a changing magnetic field, a current is induced in the wire. (This is really interesting. I kind of want to try to do this.)
   Inductors store energy in the form of magnetic fields
   If the source of a current pushing current through a wire is removed, the magnetic field will collapse. However, the collapsing of the magnetic field (changing magnetic field) induces a current.
   Inductance (L)
   

   Measured in henrys (H)

   H = Vs/A = M s = J/A^2

   Voltage across inductor:
   

   V = L (dI/dt)                (dI/dt) = rate of change of current 

   
   The energy stored in an inductor: 1/2LI^2 (formula similar to kinetic energy)
   Specifications: inductance and max current
   
   
   
   
   
   
   

Egg Drop Practice

On Monday we reviewed Chapter 8, Thinking Like an Engineer and conducted trial tests with our egg drop contraptions. Megan was sick, so Cameron helped me practice aiming when I drop the egg. He also taught me how to use the plumb bob. It was very kind of him to help out the competition. I dropped the egg from about 4 feet and it made it safely into the contraption!

Today, school was delayed due to winter weather so Robert and I were the only two people in class. We practiced dropping eggs from 16 feet in the atrium! We both missed on our first try but it was helpful to understand what we'd be facing in the real egg drop which is postponed until next lab class.

Our final product!

I missed... Next time, I will put the device closer to the wall so that I don't have to reach my arm out so far.

We dropped the egg from 16 feet!

At the end of class today, Mrs. Vestal explained to us the math behind the speed of the egg during the egg drop. She helped us derive the equation and understand the application of the principle: conservation of energy. I will post the math calculations soon.

For now, have a great day and stay warm!

Chapter 8, Thinking Like an Engineer

1. The 5 most common dimensions and the SI Units and from where  they are derived (from the introduction paragraph)
   
   
   

   

   
   
   
   
2. Force
   F=ma
   The acceleration of an item depends on the force exerted on the item and the item's mass.
   SI force unit: Newton (named after Sir Isaac Newton)
   
   

   A Newton is "the force required to accelerate a mass of one kilogram at a rate of one meter per second squared."

   
   

   A Newton is a derived unit that combines mass, length, and time.

   The SI system is "coherent" because it is possible to combine base units.
3. Describe in your own words the difference between weight and mass
   
   
   Mass is a fundamental dimension that quantifies how much matter an object contains (constant). Weight is a force that equals the mass of an object multiplied by gravity (varies based on position in the universe).
   
   
4. Density
   Density = mass/ volume
   Common units for density: kg/m^3
   
   
5. Specific Gravity
   Dimensionless ratio:

   Specific Gravity= Density of object/Density of water

   Makes it possible for any unit system to be used in calculations 
   
   Specific gravity of liquids are around 1
   

     gases are between 0.001-0.0001

     densest substances a normal person encounters are around 21.5   

     (platinum) and 19.3 (gold)
   

   
   
6. Section 8.4 briefly discuss (1) Difference in amount in grams and the amount in moles and (2) Avogadro’s Number
   
   1) Amount in grams= mass
   Amount in moles=number of units of a substance
   
   

   Comparable to the meaning of a "dozen"

   
   

   A mole contains 6.022 x 10^23 units of something. 

   
   
   2) Avogadro's Number= 6.022 x 10^23
   This number originated from the following calculation: 

   1 atomic mass unit= mass of a nucleon = 1.66 x 10^24

   
   

   For every 1 atomic mass unit there are 1.66 x 10^24 grams of that substance

   
   

   1 amu/ 1.66 x10^24 grams = 6.022 x 10^23 amu/grams

   
   

   The numerical value, 6.022 x 10^23 was labeled as the fundamental unit, mole.

   
   

   A mole is 6.022 x 10^23 units of  something.

   
   
   Avogadro's number provides a conversion factor between mass and moles of a substance.
   
   
   
7. Four temperature scales
   Celcius (named for Anders Celsius)
   Fahrenheit (Gabriel Fahrenheit)
   Kelvin (First Baron William Thomson Kelvin)
   Rankine (William J.M. Rankine)
   
   Temperature[degrees Fahrenheit] = (9/5) * Temperature[degrees Celsius] + 32
   Temperature[Kelvin] = Temperature[degrees C] + 273
   Temperature[degrees Rankine] = Temperature[degrees F] +460
   
   Both Kelvin and Rankine are absolute scales, which means at the temperature at which molecules have the minimum amount of motion possible (absolute zero) the scale records a temperature of zero.
   
   Conversion factors: 
   1 degree Celsius/ 1.8 degrees Fahrenheit
   
   

   This is because there are 100 units between the freezing point of water and the boiling point of water on the Celsius scale. However, there are 180 units between the freezing point of water and the boiling point of water on the Fahrenheit scale.

   
   

   There is one degree Celsius per 1.8 degrees Fahrenheit. 

   
   

   

   
   
   1 Kelvin/1 degree Celsius
   1 degree Rankine/1 degree Fahrenheit 
   
   
8. Pressure (the 4 forms of pressure on fluids) Section 8.6 and 9. Ideal Gas Law
   
   Pressure: force acting over an area
   SI Units of Pressure: Pascal (Pa) = N/m^2
   

   One Newton of force acting on an area of 1 square meter

   Unit Pascal is named after Blaise Pascal

   
   Pressures involving fluids:
   
   

   Atmospheric pressure- pressure exerted by weight of air above us

   Standard atmospheric pressure/average air pressure at sea level: 14.7 psi

   psi= pound-force per square inch 

   
   

   Reference points: 

   absolute pressure (perfect vacuum) 

   denoted with an "a" -- psia 

   gauge pressure (local atmospheric pressure)

   denoted with a "g" --psig 

   Blood pressure and tire pressure are examples of gauge pressure 

   
   

   Absolute pressure = Gauge pressure + Atmospheric pressure

   
   
   

   Hydrostatic pressure- pressure exerted by fluid on a submerged object

   
   

   Governed by Pascal's law:

   Hydrostatic pressure = liquid density * cross-sectional area of container 

   
   

   Total pressure- atmospheric pressure + hydrostatic pressure 

   Gas pressure- pressure exerted by gas in closed container 

   
   

   Ideal Gas Law: PV = nRT      all temperatures are recorded in Kelvin

   
   

   P= absolute pressure in Pascals

   V= volume in Liters

   n= number of moles of gas in closed container

   R= gas constant = 0.08206 (atm*L) / (mol*K)

   = 8314 (Pa*L) / (mol*K)

   T= absolute temperature in Kelvin  

   
   

   An ideal gas: one mole of a gas at a temp of 273 Kelvin and a pressure of 1 atm (atmosphere) occupies a volume of 22.4 liters 

   
   

   The Ideal Gas Law can be used to solve for any of the related units: pressure, volume, moles, and temperature. It just depends on the given situation.

Week 2 Great Egg Drop

This week, Megan and I revised our problem definition. We realized our original definition was actually our identification of the solution.

Problem Definition: Currently, Mrs. Vestal's chickens are laying eggs at various heights (less than or equal to 17 feet). Mrs. Vestal is having trouble collecting eggs because the eggs crack open when they hit the ground.

We also starting the building process for our chosen solution to the problem. Our original design looks like this:

As we put the parts together, we realized a couple of things. First, it made more sense to have a square foundation because the center basket would be more effectively attached and supported. Second, our design would be most effective if we used both a straw bottom and a tape drape for the basket. Third, we would use resources more efficiently by scrapping our plans for the top half of the structure.

Our structure's foundation is composed of straw triangles and the basket is made of straws cut in thirds as well as a tape drape interior with straw supports.

We are still working on the mathematics behind the structure and its performance.

Additionally, we tested our contraption with a real egg from 2 inches. It made it unharmed! We tried from a higher distance with the plumb bob guiding our aim, but I got nervous and completely missed the contraption! Oops.

We'll have to practice our aim this week so we'll be ready for next week's tests!


The final product looks like this:






















Megan and I are working really well together and are excited to represent Japan! We are able to listen and  build on each other's ideas. We are also very patient and optimistic in our endeavors. This project has been a great lesson on teamwork and taking things one step at a time.

Chapter 7, Thinking Like an Engineer

1. Dimensions vs Units
   
   
   Dimensions: measurable physical idea
   
   
   Unit: quantifies a dimension
   
   
   Ex) 5 (value) meters (unit) is a measure of length (dimension)
   
   
   There are 7 main dimensions.
   
   
2. SI Prefixes
   
   
   "The SI system is based on multiples of 10."
   
   
   SI prefixes are used to simplify numbers with lots of zeroes. The prefixes coincide with values in engineering notation.
   
   
   Engineering notation: ###.### x 10^M
   M is a multiple of 3
   
   
   
   
   
3. The 7 fundamental dimensions & base units (these are important)
   
   
   
   
   
   
   
4. Official SI rules
   
   
   -Abbreviations with a capital letter are named after a specific person
   -Symbols also represent plural values

   Ex) cm = centimeter and centimeters

   -Symbols do not include periods
   -Symbols are recorded in upright Roman type to separate them from mathematical symbols, which are italicized
   -A single space separates units from symbols

   Exception: degree symbols for angles are written without a space between the value and the symbol

   Ex) 25 m

   -Values are grouped by threes as shown by spaces or commas
   -Symbols for derived units that contain several units are joined by a space or interpunct (center dot)
   

   Ex) kg m or kg•m

   -Symbols for derived units that are formed by dividing various units are joined by a virgule (a slash, /) or represented by a negative exponent
   

   Ex) m/s or m s^(-1)

   -It is incorrect to combine SI prefixes
   

   Ex) millimeters (mm)

   
   
   
   
5. Difference in SI, AES and USCS. What are they? Which do you prefer? Why?
   
   
   SI (Le Systeme International d'Unites) -metric system
   AES (American Engineering System) - used by the general public in the US
   USCS (United States customary System)- "English" units
   
   
   
   
   
   I prefer the SI system because I have had years of practice converting units based on multiples of 10 that it has become second nature.
   
   
6. Unit Conversion Procedure
   
   
   "We can multiply any expression by 1 without changing the expression."
   
   
   1. Write value and unit that you would like to convert.
   2. Write the conversion formula.
   3. Make a fraction (that equals 1) out of the conversion formula so that the units will cancel (original unit in numerator/denominator and the conversion unit in the opposite place)
   4. Multiply the original value and the resulting conversion formula together
   5. Cancel units, solve the equation, and express the answer in reasonable terms

   Ex) Convert 40 yds to ft.

   
   

          40 yds x (3 ft / 1 yd) = 120 ft 

   
   
   
   
7. Unit Conversion Procedure involving multiple steps
   
   
   1. Write value and unit that you would like to convert.
   2. Write the necessary conversion formulas
   3. Make fractions (that equal 1) out of the conversion formulas so that all the units will cancel (original unit in numerator/denominator and the conversion unit in the opposite place)
   4. Multiply the original value and the resulting conversion formulas together
   5. Cancel units, solve the equation, and express the answer in reasonable terms

   Ex)

   
   
   
   
   
   
   
8. Table 7-5 is very important to an Engineer
   
   
   
   
   
   
   
9. Comment on the note of caution under the 7-5 table and the paragraph above
   
   

   Derived units: There are currently 22 derived units all of which take the name of a famous scientist or engineer. There are common derived dimensions that currently do not have a corresponding, officially named derived SI unit.

   
   

   All measurable things can be represented by a combination of the seven original dimensions. The resulting units are referred to as derived units.
   
   
   Letters represent various quantities in a variety of disciplines. Be sure to examine and understand the nature of terms in each problem.
   
   
   ALWAYS INCLUDE UNITS IN CALCULATIONS
   
   
10. What is a Dimensionless Unit? Top of page 171 A dimensionless unit is a ratio or value that is unaccompanied by a corresponding unit. A radian is a dimensionless unit. A radian is the angle formed in the center of a circle by an arc whose length is equal to the circle's radius. Therefore, a radian is a ratio of a length (length of arc) divided by a length (length of radius), a value with units but without dimension.