# Free Fall PowerPoint Position Of Free Falling Object At by MikeJenny

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Free Fall PowerPoint Position Of Free Falling Object At

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```									    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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