Motion

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Motion

• AP Physics 1

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What is Motion?

• Motion is a ___________________________relative
  to a ________________________.
• A ___________________________is a point or object
  from which motion is determined.
• A frame of reference is assumed to be __________.
• The ________________________is the most common
  frame of reference used by humans to determine
  motion.

It is said that all motion is relative because
it depends on your frame of reference.
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Displacement

• Displacement (x or y)   "Change in position"
• It is not necessarily the total distance
  traveled. In fact, displacement and distance are
  entirely different concepts. Displacement is
  relative to an axis.
• "x" displacement means you are moving
  horizontally either _____________.
• "y" displacement means you are moving vertically
  either _______________.
• The word change is expressed using the Greek
  letter _________________.
• To find the change you ALWAYS subtract
  ________________position
• It is therefore expressed as either  
  ________________________________
  _____________________________________.

Distance - _________________you travel regardless
of direction.
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Example

• Ben walks in a straight line from his locker( at
  a position  x 1.0 m) toward the physics lab(at
  a position x 9.0 m). Along the way, Sue joins
  Ben on his walk to lab from her locker (at a
  position x 5.0 m). As they arrive at the lab,
  Ben realizes he did not bring his lab notebook so
  both students walk back to Bens locker.

1. What was Bens displacement when he walked from
   his locker to the lab?
2. What was Sues displacement when she walked from
   her locker to the lab?
3. What was Sues distance traveled for her entire
   trip?
4. What was Bens displacement for his entire trip?
5. What was Sues displacement for her entire trip?

1. -4.0 m
2. 0.0 m
3. 4.0 m
4. 8.0 m
5. 12.0 m
6. 16.0 m

Are the and - signs important?
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Speed

• SPEED is simply the ____________________________.
• A rate is any quantity divided by
  ______________.
• There are three (3) types of speed
• 1
• 2
• 3.

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• Speed Vs. Velocity
• Is there a difference between speed and velocity?
  If yes, what is the difference?

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Velocity

• Velocity is defined as

Average SPEED is simply the
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Average Acceleration

• Acceleration is the _____________________
• _____________.

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What do the signs( or -) mean?
Quantity Positive Negative
Displacement You are traveling north, east, right, or in the x or y direction. You are traveling south, west, left, or in the x or y direction.
Velocity The rate you are traveling north, east, right, or in the x or y direction. The rate you are traveling south, west, left, or in the x or y direction.
Acceleration Your velocity(speed) is increasing in a positive direction or your speed is decreasing in a negative direction. Your velocity(speed) is decreasing in a positive direction or your speed is increasing in a negative direction.
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The Acceleration due to gravity ag or g

• The acceleration due to gravity is a special
  constant that exists in a ______________, meaning
  without air resistance. If an object is in FREE
  FALL, gravity will CHANGE an objects velocity by
  _____________________.

• The acceleration due to gravity
• ALWAYS ___________________.
• IS ALWAYS ________________ near the surface of
  Earth

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Consider an object thrown straight up into the
air. (Neglect Air Resistance)

1. As the object is thrown is the velocity positive
   or negative?
2. As the object rises, what is happening to the
   speed of the object? Why?
3. At the highest point the object reaches, what is
   its speed, velocity, and acceleration?
4. What are some things you can say about the
   object if it is caught at the same height it was
   thrown?