1. Engineering Education

1.1 Problem Solving Philosophies

1. Even when problems seem impossible keep trying, it will help you learn to solve problems (This is like learning a new sport, except here you are building strength and coordination for problem solving). Solving problems is mainly a skill of recognizing patterns and then using techniques you have seen before.

2. If there is a topic you do not understand in a previous section, it will make it hard to solve problems in more advanced sections.

3. As you solve problems, you will find that you work faster.

4. Avoid shortcuts, they always take longer.

5. Try alternate ways of solving problems, this will strengthen your skills.

6. If you are really stuck on a problem leave it until the next day, then try again.

7. Solve problems with variables, and units, this will reduce errors, and makes errors easier to find and fix.

8. Solving problems is the only way to do well.

9. Always look at your answer to see if it makes sense, and find ways to check the results.

10. Always use Free Body Diagrams, and list assumptions, this will reduce assumption based mistakes in simple problems, and give you clues for solving complicated problems.

11. Carefully read the question before starting. If it is confusing, underlining or writing out the details in point form can help.

1.2 Studying Engineering in Courses

• A student who will get an ‘A’ grade will typically focus on the material in the course, more than on the marks it is worth.

 

• These students typically focus on the value of assigned work and then decide what to work on next. Their work habits are commonly described as ‘firefighting’. While this method appears to be the most efficient, the rush-to-submit often decreases the learning value significantly for the time spent.

 

• These students are rarely in class and count on others to keep them up to date. They typically measure their performance by asking other students how they are doing, and are often heard to say things like: “I can always ride the bell”, “they can’t fail us all”, “I don’t need to go to lectures”, and “It’s OK I took this course before”.

 

1.3 A Taxonomy of Mechanical Engineering

• The simple hierarchical list below tries to divide some of the fundamental topics found in engineering. It should be noted that this sort of division is somewhat subjective, although suitable for our purposes.

Engineering

Design

technology

systems

Analysis

solid mechanics

rigid solids

statics

equilibrium

trusses

method of joints

method of sections

frames

method of members

friction

dynamics

translation

rotation

collision

flexible solids

statics

Hooke’s law

dynamics

collision

vibrations

fluids

compressible flow

incompressible flow

hydraulics

thermodynamics

Methods

metrology

laboratory techniques

manufacturing processes

1.4 Engineering Calculations

• we will use both SI Units and Imperial units,

• Typical SI (System International) units are,

m: meter (or mm, cm, km)

s: second (or min, hr, day, yr)

kg: kilogram (or g, tonnes)

N: Newton (kg m/s2)

• Typical Imperial Units are,

lb: pounds (or tons, oz.)

in: inches (or ft, yd, mile)

s: second

slug: mass (note: this is a proper unit of mass although we commonly use pounds)

• These units can be combined to describe any numbers we have.

• Note: the reader is expected to be aware of the basic rules of numbers and units.

• see the section on units and watch some of the sample calculations for examples of proper application.

• significant figures should be considered. One example of the effect of ignoring significant figures is given,

 

• Basic rules of calculations for engineering,

1. To count the number of significant figures, don’t count zeroes at the start of the number, but do count zeroes at the end.

2. When doing calculations, the number of significant figures should be considered. All numbers and results should have the same number of significant figures, or one/two extra for more accurate numbers.

3. Generally, the final result must have at most the same number of significant figures as the least significant number.

4. Typical engineering numbers have 3 or 4 significant figures as they are determined from real systems experimentally.

5. Be aware that different operations may increase or decrease accuracy.

6. Engineers use engineering notation for numbers in exponential form, for example 0.0003 should be 0.3x10-3 not 3x10-4.

1.5 Fundamental Theories

• The fundamental laws,

 

 

 

• Newton’s Law of Gravitational Attraction: basically the force of attraction between two bodies is a function of separation.