2.1-2.6

Tip: Open up YouTube, and adjust the speed to get through videos faster!

Homework:

Read Chapter 2 notes:
Watch some youtubes:    

Lost of options to choose between: 

TxTech:

• Statics: Lesson 1- Intro and Newton's Laws, Scalars, and Vectors
• Statics: Lesson 2- Vector Language, Intro to Vector Addition
• Statics: Lesson 3-The Triangle Rule and Adding Vectors to find a Resultant
• Statics: Lesson 4- Vector Addition, Triangle Rule, and Cartesian and Vector Notation
• Statics: Lesson 5 - 2-D Find Resultant Vectors, Triangle Rule, Cartesian Components
• Statics: Lesson 6 - Finding Vector Components in Non-Orthagonal systems
• Statics: Lesson 7 - Most Missed topic in Statics, Cartesian Components

Randall:

Force vectors 1: 

Force Vectors 2:

Force vectors 3:

Particle Equilibrium 1

Particle Equilibrium 2

Particle Equilibrium 3

Yiheng:

Lec 4: Vector operation 3:38
Lec 5: Cartesian vectors and operations

Lec 6: Position and Force vector
Lec 8: FBD's

Lec 9: Particle Equilibrium

Another statics resource:

Unit-1 Basics & Statics Of Particles (Resolution of Forces) - Engineering Mechanics

https://www.youtube.com/watch?v=4LTXVznGimw 

Vectors:
https://ecourses.ou.edu/cgi-bin/display_lectures.cgi?course=st&status=disp_ch

If you find a better YouTube, post it in Ch2 for D2L points!

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2.1-2.3: Vocabulary~~~~~~~~~~~~~~~~~~~~~~~

resultant force

•  replacing multiple forces acting on a particle with a single equivalent force
• Make a parallelogram, 
• resultant = diagonal of parallelogram

note: the magnitude of the vector
P + Q is NOT equal to the sum of the magnitudes of P+Q, you need to think about directions. 

equilibrium

Summation of forces acting on a particle is 0.  State of rest.

particle

Size & shape insignificant, all forces assumed to be applied at a single point.



force

Vector quantity

action of one body on another; characterized by:

• point of application 

• magnitude 
• SI units: 1,000N = 1 kN
• U.S. customary: 1,000 lb = 1 kip
  
• Direction of Force
• line of action  - line force acts along
•  sense: arrow pointing which way it is acting; ↑? ↓?

Scalar 

• has magnitude but not direction.   
• Examples:  
• mass, 
• volume, 
• temperature

Vector 

• has magnitude and direction
• add according to the parallelogram law.
• Examples:   
• displacements
• velocities
• accelerations

Vector classifications

• Fixed or bound vectors 

 well defined points of application that cannot be changed without affecting an  analysis.

• Free vectors 

may be freely moved in space without changing their effect on an analysis.

• Sliding vectors 

may be applied anywhere along their line of action without affecting an analysis.

2.4 Addition of vectors ~~~~~~~~~~~~~~~~~~~~~~~~
Trapezoid rule for vector addition

Triangle rule for vector addition
 - Just draw half of the parallelogram
- arrange vectors head to tail

Vector addition is commutative
 

Vector subtraction 

     → Just change which way the arrow points ←

 

Sum of three or more vectors

Add two together, and then add on the third etc.
 
P + Q + S = (P + Q) + S


 

It doesn't matter what order you add them

 
Product of a Scalar and a Vector

•  Keep the same line of action

• Change the magnitude

concurrent forces
all forces pass through a common point

Resultant of concurrent forces:

Replace multiple forces with single force,
.
R → same effect as S+P+Q on "A"

Resolution of a force into components

Describe force in terms of x, y, z

Trig Review~~~~~~~~~~~~~~~~~~~~~~~~~~.
 Law of cosines

Law of sines

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