Ch 14 Oblique Triangles and Vectors

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Ch 14 Oblique Triangles and Vectors

• Section 4 Introduction to Vectors

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Vectors

• Vectors are used to describe
• Motion
• Applied Forces
• Electronics Measurements

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Vectors - Characteristics

• A vector has two components
• Scalar Quantity
• Direction

115 mi/h
Due East
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Vectors - Characteristics

• A vector has two components
• Scalar Quantity
• Direction

150 lb
270? (straight down)
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Vector versus Scalar

• An airplane traveling at 215 mi/h
• Scalar Vector
• An applied force of 15 lbs applied to a beam at
  45?.
• Scalar Vector
• A north wind

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Drawing Vectors

• Airplane traveling at 100 mi/h due North
• Wind blowing from the west at 25 mi/h

Scale 1 25 mi/h
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Displacement

• Displacement of an object describes the distance
  and direction from a starting point

An air traffic controller instructs a plane pilot
leaving Madison to fly 300 miles due west, then
fly 400 miles due north.
Displacement
500 miles
?
Madison
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Vector Addition

• Bold, upper case letters used to indicate a
  vector
• A
• B

A B
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Resultant

• The resultant vector is determined by the initial
  point of the first vector and the terminal point
  of the last vector.

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Adding Vectors

• A B C

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Parallelogram Method

• Alternative to the tail to head method.

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Additional Topics in Addition

• Vector A
• 2A

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Vector Addition Continued

• For vectors A and B, find 3A 2B

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Vector Addition Continued

• For vectors A and B, find 3A 2B

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Vector Subtraction

• For vectors A and B, find A B
• A B A (-B)

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Application

• Airplane is pointed due north with an airspeed of
  140 mi/h.
• It is blown off course by a wind of 35 mi/h which
  is from a direction of 45? south of west.
• Determine the true speed of the airplane.

165
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Practice

• MathXL Ch 14 Section 4 Homework