Chill: Energy and Sig Figs Arises Essay

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Pages: 5

ENGR 112
Day One
Dr. Spindel, Dr. From UVA, in biomedical engr
Room 357 ISAT/CS

Blackboard and canvas will both be used
Install/ SolidWorks
Notebook and graph notebook
******BUY Safety Classes
Learn and teach
Work Together
Quiz everyday

Engineer comes from the latin word Inginiator
Meaning the ingenious one

Synthesis- putting things together
Analysis- taking things apart.

Talking about units
Sig Figs.
2nd law of motion.

Day 2
Engineers look at systems mathematically and try to the systems to improve them.
Car system fuel goes in
Exhaust out
Mechanical power
Thermal power
Almost everything is a system
Most things are open systems
Earth is a system with land, water, urban, and agricultural systems with in it

Engineers speak in precise language so that information can be passed along easily with out confusion

Chapter one

Engineer refers to someone who is a creative, ingenious person who finds solutions to practical problems

Today it refers to some one who uses creative design to and analysis processes that incorporate energy, materials motion and information to serve human needs.
Engineering is not a spectator sport, it is hands on and minds on
Conceptual sketch- a visual expression that details the elements and relationship’s involved in a problem. This is the first step in an engineers approach.
Often it doesn’t even look like what it portrays but it is intended to 1. Help engineer identify the elements of a problem 2. See how groups of elements are connected together 3. Understasnd how all said subsystems work to create a working system.
Engineers are also subject to personal ethics, which vary from country to country and they must act in a way the is morally sound based on their environment Ethics solutions 1. Do what you say you will 2. Never divulge information given to you in confidence 3. Accept responsibility for your mistakes 4. Never become involved in a lie 5. Never accept gifts that compromise your ability to perform in the best interests of your org.

Chapter 2
Elements of engineering

Numerical value- answering numerical questions requires the correct numerical value. Variables- Engineers typically ask questions like “how hot will it get” or How heavy will it be? Each of these questions involve a variable or a precisely defined quantity describing an aspect of nature. How heavy?- answered using the variable for weight or mass How hot? Use variable for temperature

Units- The fundamental laws of nature are independent of the system of units
In engineering a calculated quantity always has two parts 1. The numerical value 2. And its associated units (m, m/s, kg)
And each must be correct otherwise the calculated quantity is incorrect.
Units help quantify the underlying concept of Dimensions.
Dimensions are the fundamental quantities we perceive such as mass or height
Units provide a numerical scale whereby we can carry out a measurement of a quantity in some dimension

Fundamental units

Si unit Prefixes

Sig figs- Introduces the concept of analysis
The concept of sig figs arises because math alone does not increase the accuracy of a measured quantity.
Leading zeros (.00069) are not sig figs
Trailing zeros such as in 12300 is obscure because you cannot tell If that was the real measurement or an estimate
Precision-refers to how many times we can repeat a number using spate measurements.
So if 12300 was precise to +/- 100 it would have 3 sig figs but if it were precise to +/-10 it would have 4
Rules – 1. the sum or difference should contain no sig figs further to the right of the decimal then the least precise number
Ex. 12.1 + 13.23= 25.3 not 25.33 2. the product or quotient should contain no more sig figs than contained by the term with the leat sig figs ex. 113.2 x 1.43 = 162 not 161.876 because 1.43 only contains 3 sig figs