Instructional Objectives : 1.Research on motion and force 2. Research using virtual investigations

1

• Instructional Objectives 1.Research on motion
  and force2. Research using virtual
  investigations
• Homework
• Monday- Notes 79-81 Ch.11)
• Vocabulary
• Tuesday- Notes 82-83 Study Vocabulary
• Wednesday- Speed and velocity worksheet
• Thursday- Speed, Velocity, and acceleration
  worksheet

2
Motionprocess of changing place

• Distance how far something has moved (This does
  not deal with direction!!!)
• Displacement how far something has moved in a
  DIRECTION

3
Measuring Displacements

• Think about the motion of a roller coaster car.
• The length of the path along which the car has
  traveled is distance.
• Displacement is the direction from the starting
  point to the car and the length of the straight
  line between them.
• After completing a trip around the track, the
  cars displacement is zero.

4
Combining Displacements

1. Add the magnitudes of two displacement vectors
   that have the same direction.
2. Two displacement vectors with opposite directions
   are subtracted from each other.

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Location

• Position an objects location
• Reference Point a known position used to locate
  something
• Ex - The car is next to the blue truck.

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Rate

• A rate is how often something happens.
• Ex 4 meters every second or 12 drops every
  minute.

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SPEED

• the rate that something changes its position
• Ex 50 miles per hour

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Two types of speed

• Instantaneous speed the rate of motion at a
  given instant in time (happens right now).
• Constant speed unchanging speed

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Average speed

• the total distance traveled divide by the total
  time
• is what we can calculate.

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Scaler and Vector

• Scaler a measurement that has no specific
  direction
• Vector a measurement having a specific
  direction

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Calculating Speed

• Speed Total Distance
  . Total Time
  
• Speed Units are
• miles/hour,
• meters/second,
• feet/minute, and other such units.

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• Instructional Objectives 1.Learn the
  difference between positive and negative
  accelerations2. Learn the difference between
  speed and velocity

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Speed Problem 1

• A truck travels 40 Km. in 20 minutes. Find
  its speed.
• Solution Speed 40 Km. .
  20 min. Speed 2 Km./min.

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Speed Problem 2

• An airplane is traveling at 200 miles/hr. for 5
  hours. How far does it travel?
• Solution200 m/hr Distance (Dist. Speed
  x T.) 5 hr. Distance 1000 miles

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Speed Problem 3

• How long does it take a boy to run 500 meters at
  5 m/sec?
• Solution 5 m/s 500 m .
  Time (Time x 5 m/sec
  500 m) Time 100 seconds

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Velocity 1

• Velocity speed in a certain direction
• (Velocity ALWAYS has a DIRECTION !!!!!!)
• Ex 5 miles/hr East or 20 meters/sec downward.

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Velocity 2

• Velocity MUST ALWAYS show a DIRECTION!!!!!!!! If
  it does not show a direction, you have reported a
  SPEED!!!!!!!!!!!

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Velocity Problem 1

• A turtle crawls 200 meters North in 20 minutes.
  Find its velocity.
• Solution Speed 200 meters (Add direction)
  20 mins. Velocity 10 m/min. North

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Speed Graphs 1

• Distance on Y-axis Time on X-axis.
• Slope of line is Speed!

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Speed Graphs 2

• Slope of Red Line is 2400 - 0 m.
  30 - 0 min. Or 80 m/min (this is
  speed)

21

• Instructional Objectives 1.Identify positive
  and negative accelerations2. Learn the
  difference between speed and velocity

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What is Acceleration?

• Change in Speed-
• Ex negative acceleration and positive
  acceleration
• Constant speed means zero acceleration
• Change in direction -car traveling in a circle
• Change in Speed and direction -Ex Roller coaster
• Constant Acceleration -Steady change in velocity

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What is ?
Acceleration

• Acceleration the rate of change in velocity
• Positive Acceleration is a Gain in speed.
• Negative Acceleration is a Loss in speed.

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Calculating Acceleration 1

• Use the following formula accelerationvelocity
  change .
  time or a vf
  - vi
  . t

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Acceleration Units

• Acceleration Units m/sec2, miles/hour/sec.,
  yards/min.2, or such as this

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Positive Acceleration

• is when velocity increases.

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Negative Acceleration

• is when velocity decreases.
• Always subtract velocities first then divide by
  the time.

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Acceleration Problem 1a

• A motorcycle accelerates from 20 miles/hr to
  80miles/hr in 6 seconds. What is its rate of
  acceleration?

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Answer to Problem 1a

• Acc. Vf - Vi 80 - 20 m/h
  . t 6 sec
  Acc. 60 m/h 10 m/h/sec
  . 6 sec acceleration .
  is positive.

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Acceleration Problem 2a

• A car slams on brakes when traveling at 200
  meters/sec and stops in 10 seconds. What was the
  cars rate of acceleration?

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Answer to Problem 2

• Acc. Vf - Vi 0 -200 m/sec . t
  10 sec Acc- 200 m/sec
  -20m/s/s . 10 sec or -20 m/s2
  . (Acceleration is negative.)