Displacement and Velocity (12.4)

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Displacement and Velocity (12.4)
Straight Line
Curved Line
Constant Speed Average speed (Vav)
instantaneous speed Slope measured from graph
line
Non-constant speed (changing) Average speed
(Vav) ? instantaneous speed Slope measured from
tangent line
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Displacement (12.4)
Scalar Quantity
- has both a number and a unit.
Distance is a scalar quantity
We say that distance has a magnitude (number and
unit). It is a scalar property.
Vector Quantity
- has both a magnitude and a direction.
Distance is not a vector quantity
Distance has only magnitude (number and unit).
It is a scalar quantity.
Displacement is a vector quantity
Displacement has both magnitude and direction.
It is a vector quantity.
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Schools Out!
Distance (?d) 3.5 km
Displacement (?d) 500 m North
After a fun day of exciting science classes,
_________ walks home from school.
Displacement is a change in position
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Displacement (12.4)
Distance (?d) Displacement (?d)
Number (value) ? ?
Unit ? ?
Magnitude ? ?
Direction ?
Scalar Quantity ?
Vector Quantity ?
Displacement does not depend upon the path taken
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Displacement (12.4)
Find the displacement of the train from point (a)
to point (b)

• What is our reference point (origin)?
• What is the positive direction and what is the
  negative direction?
• Use our equation
• Solve using our values from the picture

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Velocity (12.4)
Scalar Quantity
- has both a number and a unit.
Speed is a scalar quantity
We say that speed has a magnitude (number and
unit). It is a scalar property.
Vector Quantity
- has both a magnitude and a direction.
Speed is not a vector quantity
Speed has only magnitude (number and unit). It is
a scalar quantity.
Velocity is a vector quantity
Velocity has both magnitude and direction. It is
a vector quantity.
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Velocity (12.4)
Speed (v) Velocity( )
Number (value) ? ?
Unit ? ?
Magnitude ? ?
Direction ?
Scalar Quantity ?
Vector Quantity ?
Velocity does not depend upon the path taken
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Rise ?d
Run ?t
What is the average velocity of the hiker after
20 minutes?
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Speed and distance will always be
positive Velocity and displacement can have
negative values
WHY?
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Uniform Motion
- an
object has uniform motion if it is traveling at
constant velocity.
Uniform Motion Constant Velocity
If an object is traveling at constant speed with
a constant direction then it has constant
velocity.
Uniform Motion?