Transcript Slide 1

Copyright © 2011 Pearson, Inc.
Goal: Apply the arithmetic of vectors.
6.1 Day 1
Vectors in the
Plane
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What you’ll learn about




Two-Dimensional Vectors
Vector Operations
Direction Angles
Applications of Vectors
… and why
These topics are important in many real-world
applications, such as calculating the effect of the wind on
an airplane’s path.
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Slide 6.1 - 3
One vs. Two Quantities
Magnitude (Size)
 temperature
 distance
 Speed
 mass
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Magnitude & Direction
 force
 velocity
 weight
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Vector -
magnitude:
direction:
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Slide 6.1 - 5
Vocabulary
Component Form:
Components:
Standard representation:
Zero vector:
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Initial Point, Terminal Point,
Equivalent
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Head Minus Tail (HMT) Rule


If an arrow has initial point x1 , y1 and term inal point
x
2

, y 2 , it represents the vector
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x 2  x1 , y 2  y1 .
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Example 1: Showing Vectors are
Equivalent
Show that the arrow from R = (-4, 2) to S = (-1, 6) is equivalent
to the arrow from P = (2, -1) to Q = (5, 3).
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Magnitude
If v is rep resen ted b y th e arro w fro m
x , y  to x
1
1
2

, y2 ,
th en
v 
x
2
 x1
  y
2
2
 y1
If v  a , b , th en v 
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.
2
a b .
2
2
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Example 2: Finding Magnitude of a
Vector
Find the m agnitude of v represented by P Q ,
w here P  (3, 4 ) and Q  (5, 2 ).
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Slide 6.1 - 11
Vector Addition
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Vector Addition
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Example 3: Performing Vector
Addition
Let u = −1, 3 and v = 4,2 . Find u + v.
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Parallelogram Representation
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Scalar Multiplication
scalar:
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Example 3: Performing Vector
Operations
Let u = −1, 2 and v = 3,2 .
 Find 2u.

2u - v
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Slide 6.1 - 17
Exit Ticket
Performing Vector Operations
Let u  2,  1 and v  5, 3 . Find 3u  v .
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Slide 6.1 - 18
Goal: Use vectors to solve real-world problems.
6.1 Day 2
Vectors in the
Plane
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Resolving the Vector-
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Slide 6.1 - 20
Example 5a: Finding the Components of a
Vector
Find the components of the vector v with direction angle 115˚
and magnitude 6.
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Example 5b: Finding the Components of a
Vector
Find the exact components of the vector v with direction
angle 30˚ and magnitude 8.
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Example 5c: Finding the Components of a
Vector
Draw the indicated vector and show the components into which it
is resolved.
A cannonball is launched with a speed of 170 m/s at 40°
above the horizontal.
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Slide 6.1 - 23
Velocity and Speed
The velocity of a moving object is a vector
because velocity has both magnitude and
direction. The magnitude of velocity is ________.
________________ - the angle that a line of travel
makes with due north, measured clockwise
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Slide 6.1 - 24
Example 7: Writing Velocity as a
Vector
A DC-10 jet aircraft is flying on a bearing of 65˚ at 500 mph.
Find the component form of the velocity of the airplane.
Recall that the bearing is the angle that the line of travel makes
with due north, measured clockwise.
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Slide 6.1 - 25
Calculate Magnitude and Direction.

Calculate the magnitude and direction of the vector.
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Example: Find the magnitude and direction
angle of each vector.
a)
12, 4
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b)
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Summary


Magnitude and direction → 𝑎, 𝑏
𝑎, 𝑏 → magnitude and direction
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Goal: Calculate the resultant vector.
6.1 Day 3
Vectors in the
Plane
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Resultant Vector
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Example: Add the Vectors to find the
Resultant Vector
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Example: Calculating the Effect of Wind
Velocity
A jet carrying Dora the Explorer is flying at 400 mph on a course
with a bearing of 30º. If the jet experiences a crosswind blowing
due south at 20 mph, find the resultant speed and direction of the
jet. Round all values throughout the problem and the final
answer to the nearest tenth.
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: Combining Forces
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Solution
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