Motion In Free Fall
John Naoum
Instructor: Sunip Mukherjee
Partners: David Bailey, Joshua Riviera
Objective:
The acceleration due to gravity (g) will be determined.
OCTOBER 2, 2017
PHYS 1410 – SECTION 806
UNIVERSITY OF MASSACHUSETTS LOWELL

Introduction
If an object is acted upon by a net force, it will accelerate due to that force. If the
magnitude of the force is constant, then the acceleration of the object will be constant. An object
that falls freely is acted upon by the force of gravity, which is the attraction between that object
and the center of the earth. There is another force that is being ignored, called air resistance,
which also acts on a falling object. The reason that it is ignored is because smooth, dense, objects
falling a short distance will have a very small amount of air resistance, therefore we can factor
out the magnitude of this force during the experiment.
The first graph shows the curves of the relationship between displacement and time, and
velocity and time, for an object moving at a constant acceleration. The definition of acceleration
is the rate of change of the velocity over time. For example:
a
=
v – v
o
t
v
=
v
o
+
at
In these equations, (a) represents the acceleration of the object, which the velocity changes from
the initial value (v
o
) to the final value (v) in the interval of time (t). The first equation shows a
plot of v -vs.- t which should be a straight line, since the acceleration is constant. The slope of
the line is equivalent to the acceleration a. The average velocity of an object is also known as the
total displacement (s) travelled by the object divided by the time it took for it to travel that
displacement. An example of this equation:
´
v
=
s
/
t

For uniformly accelerated motion, the average velocity is the mean of the initial and final
velocities (v
o
and v) over the time interval.
´
v
=
v
0
+
v
2