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Free Fall PowerPoint Position Of Free Falling Object At

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Free Fall PowerPoint Position Of Free Falling Object At Powered By Docstoc
					    The four kinematic equations which
     describe an object's motion are:




   There are a variety of symbols used in the above equations and each symbol
    has a specific meaning.
   d – the displacement of the object. (we use “x” & will also use “y”)
   t – the time for which the object moved.
   a – the acceleration of the object.
   vi – the initial velocity of the object.
   vf – the final velocity of the object.
 The four kinematic equations which
  describe an object's motion are:
If there is NO AIR
    RESISTANCE ALL
    objects, regardless of
    weight & size, will fall at
    the same acceleration.

The Acceleration of
  gravity:

  g= -9.81 m/s/s
    Position Of Free Falling Object
      At Regular Time Intervals
   The position of the free-
    falling object at regular
    time intervals, every 1
    second, is shown. The
    fact that the distance
    which the ball travels
    every interval of time is
    increasing is a sure sign
    that the ball is speeding
    up as it falls downward.
Velocity Of Free Falling Object At
     Regular Time Intervals

   Assuming that the
    position of a free-falling
    ball dropped from a
    position of rest is shown
    every 1 second, the
    velocity of the ball will
    be shown to increase
    Velocity Of Free Falling Object At
         Regular Time Intervals
   Observe that the line on the graph is curved. A curved line on a position
    vs. time graph signifies an accelerated motion. Since a free-falling object
    is undergoing an acceleration of g = 10 m/s/s (approximate value), you
    would expect that its position-time graph would be curved. A closer look
    at the position-time graph reveals that the object starts with a small
    velocity (slow) and finishes with a large velocity (fast). Since the slope of
    any position vs. time graph is the velocity of the object, the initial small
    slope indicates a small initial velocity and the final large slope indicates
    a large final velocity. Last, but not least, the negative slope of the line
    indicates a negative (i.e., downward) velocity.
Velocity Of Free Falling Object At
     Regular Time Intervals
   look at the velocity-time graph reveals that the object starts with a
    zero velocity (starts from rest) and finishes with a large, negative
    velocity; that is, the object is moving in the negative direction and
    speeding up. An object which is moving in the negative direction and
    speeding up is said to have a negative acceleration


   This analysis of the slope on the graph is consistent with the
    motion of a free-falling object – an object moving with a constant
    acceleration of 10 m/s/s in the downward direction.
                             How Fast?
   The velocity of a free-falling object
    which has been dropped from a
    position of rest is dependent upon the
    length of time for which it has fallen.
    The formula for determining the
    velocity of a falling object after a time
    of t seconds is:

   vf = vi + gt
   where g is the acceleration of gravity
    (approximately -10 m/s/s on Earth; its
    exact value is -9.81 m/s/s). The
    equation above can be used to
    calculate the velocity of the object
    after a given amount of time.
           How FAST ? Example
   t=6s

   vf = (0 m/s) + (10 m/s2) (6 s) =   60 m/s


   t=8s

   vf = (0 m/s) + (10 m/s2)(8 s) =   80 m/s
                           How Far?
   The distance which a free-falling
    object has fallen from a position of
    rest is also dependent upon the
    time of fall. The distance fallen
    after a time of t seconds is given
    by the formula below:

   x = (1/2) g t2
   where g is the acceleration of
    gravity (approximately -10 m/s/s on
    Earth; its exact value is -9.81
    m/s/s). The equation above can be
    used to calculate the distance
    traveled by the object after a given
    amount of time.
             How FAR ? Example
   t=1s

   x = (1/2) (-10 m/s2) (1 s)2 =   -5 m     The
                                             NEGATIVE
   t=2s                                     displacement,
                                             indicates that
   x = (1/2) (-10 m/s2) (2 s)2 =   -20 m    the object is
                                             falling DOWN
   t=5s

   x = (1/2) (-10 m/s2) (5 s)2 =   -125 m

				
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Description: Free Fall PowerPoint Position Of Free Falling Object At