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					Standard Strand 1: Motion
      1. An object in motion changes
         position relative to a reference
         point.
      2. Speed measures how fast
         position changes.
      3. Acceleration measures how fast
         velocity changes.
Warm-up:
   Choose an object in the class that is easy
    to recognize.
   Without writing what it is, write directions
    to the object from your seat.
   Share your directions with your tablemate.
    Can he/she identify the original object?
   Change your directions until your partner
    locates your object.
   Can you locate your partner’s object?
    Modify the directions until you can.
JOURNAL(continued) :
   What is position?

   How do you describe a position?

   How would your describe motion in terms
    of position?
Key Terms:
     Direction            Motion


     Displacement         Velocity


     Position             Slope


     Acceleration         Vector


     Speed                Reference point
      – Average
      – Instantaneous      Magnitude
      – Constant
Motion
   Is a change in position with time (meaning
    there is time interval involved - not
    instantaneous)

   Is observed relative to a reference point:

    – Are you in motion sitting quietly in your seat?
       • From the viewpoint of the teacher? Your table
         partner?
       • From a viewpoint of an observer on the International
         Space Station?
Reference point:
 Point from which motion is
  detected/compared
 The most common reference point is the
  Earth
 Motion is said to be relative to a reference
  point
 Examples:
    – You are driving in a car. The driver is not
      moving in comparison to you (RP1), but is
      moving (as are you) relative to a person (RP2)
      standing on the street who sees the change in
      position
Reference Point Activity
   The teacher tosses the ball in the air.
    Describe the motion of the ball from the
    teacher’s and the your position as
    reference points.

   The teacher walks across the room
    tossing a ball up and down. Describe the
    balls motion - From both reference points.
What other terms are involved in
motion?
   There is a change in position over time
    which implies a distance has been
    covered….Distance from position 1 to 2, 3,
    4 and so on…..

   There is a time interval.

   What is the quantity known as distance/
    unit time?
Speed
   Distance traveled over time

   What is average speed?

   What is constant speed?

   What is instantaneous speed?

   How would you graph speed?
Speed = distance/time
   Our variable are: distance and time

   Which is the “X” axis variable?
    – Manipulated variable (independent
      variable)


   Which is the “Y” axis variable?
  D
  i        What is slope?
  s
  t
  a
  n
  c
                                  X
  e
                        Y
(Meters)



                 Time (seconds)
Slope
   The slope of a line is calculated by
    dividing the change in Y (distance
    between the Y’s) by the change in X

             Y        Yf - Yi         RISE
                  =               =
              X        X f - Xi       RUN
Slope : Rise (Y)/Run (X)
   The slope of a line on a distance/time graph
    indicates the speed (d/t) of the object.

   Average speed: over time interval (speed/slope
    changes)

   Instantaneous speed: at a particular point

   Constant speed: straight line

   Slope = 0, no motion

				
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posted:4/23/2013
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