PH 101

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PH 101

• Wednesday, January 25, 2006
• Start Chapter 3.
• Section 3.1 Vectors
• Section 3.2 Components

Powerpoints are on web site
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Two dimensions person walks 10 km east and
then 5 km north. What is displacement?
Parallel displacement does not change a vector.
Vectors are added by adding their components.
Vectors can be multiplied by a scalar.
Each component of the vector is multiplied by the
scalar.
Multiply vector by (-1) get vector with
same magnitude but opposite direction.
Two vectors are equal if both magnitude
and direction are the same.
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How do you get the magnitude (length) of the
displacement?
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How to get the angle T with the x-axis?
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How to get Vector Components?
V 10 m/s at 300 N of E Vx V cos T 10 m/s
0.866 8.66 m/s E Vy V sin T 10 m/s 0.5
5 m/s N
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Addition of vectors parallelogram method
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Subtracting vectors v1 v2 v1 ( v2)
y
x
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Trigonometric Functions
V
Vy
Vx
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Example An object moves for 10 km at an angle
of 150 relative to the x-axis of a frame of
reference. After completing the first leg of the
trip the object moves for another 5 km at an
angle of 600 relative to the x-axis of the same
frame of reference. What is the displacement
during this trip? (Magnitude and angle)