Physics Study Guide

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Physics Study Guide

• Chapter 2 Section 1

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Chapter 2 Section 1

• Frame of reference
• A coordinate system for specifying the precise
  location of objects in space
• No reference frame is more correct than another

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Chapter 2 Section 1

• Path length
• Total distance an object covers
• Always positive

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Chapter 2 Section 1

• Displacement
• Change in position of an object
• Measured as straight line drawn from initial to
  final position
• ?x xf xi where ? (delta) means change

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Chapter 2 Section 1

• Doesnt usually equal path length
• Should include description of direction

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Chapter 2 Section 1

• You make a trip to the store and then return
  home. What is your displacement?

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Chapter 2 Section 1

• Average speed
• Change in path length divided by the
  corresponding change in time
• Avg speed path length
• time

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Chapter 2 Section 1

• Average velocity
• Total displacement divided by the corresponding
  change in time
• Avg velocity displacement
• time
• V ?x
• ?t

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Chapter 2 Section 1

• Can be positive or negative depending on
  displacement
• You drive to a friends house 370 km to the west.
  If you left at 10 am and arrived at 3 pm, what
  is your average velocity?

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Chapter 2 Section 1

• A car travels 100 km. If the first half of the
  distance is driven at 50 km/h and the second half
  is driven at 100 km/h, what is the average
  velocity?

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Chapter 2 Section 1

• Heather and Matthew walk eastward with a speed of
  0.98 m/s. If it takes them 34 min to walk to the
  store, how far have they walked?

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Chapter 2 Section 1

• If Joe rides south on his bicycle in a straight
  line for 15 min with an average speed of 12.5
  km/h, how far has he ridden?

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Chapter 2 Section 1

• Simpson drives his car with an average velocity
  of 48 km/h to the east. How long will it take
  him to drive 144 km on a straight highway?

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Chapter 2 Section 1

• A bus travels 280 km south along a straight path
  with an average velocity of 88 km/h to the south.
  The bus stops for 24 min, then it travels 210 km
  south with an average velocity of 75 km/h to the
  south. How long does the total trip last? What
  is the average velocity for the total trip?

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Chapter 2 Section 1

• Velocity can be studied by looking at a position,
  time graph

Vslope of position, time graph for that
?t Slope rise ?x v run
?t
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Chapter 2 Section 1

• Instantaneous velocity
• Velocity of an object at some specific point
• Slope of tangent line at that point on position,
  time graph