Lab 1: FreeFall Acceleration
INTRODUCTION:
In this lab, we will measure the acceleration of earth’s gravity. Using a piece of
paper tape, with a weight suspended on the end, we will drop it from some point. A
machine will make dots on the paper at even intervals as it falls. The distance between
the dots represents the distance the paper fell during each interval. By graphing the
distance between the dots as the interval number increases, we can find a value for
gravity using the slope of the bestfit line. This calculated number should theoretically be
the same as the universally accepted value for gravity.
THEORY:
This lab deals with finding the constant acceleration at which things fall towards
earth, or the measure of gravity. The equation for the force of gravity between an object
of mass
m
and the earth of mass
M
is F = GMm/R
2
, where
G
is the universal gravitational
constant and
R
is the radius of the earth. The
R
in the denominator actually stands for the
distance between the two objects, but for an object near earth’s surface, we can assume
the distance to equal earth’s radius. Finding the value of gravity requires dividing both
sides of the equation by
m
(since F=mg). This gives g = GM/R
2
.
Newton’s second law states that F = ma, or in terms of acceleration: a=F/m. This
means that an object of mass
m
with a force
F
acting upon it has an acceleration equal to
a
. Since gravity is the acceleration of objects towards earth, we can set Newton’s second
law and law of gravitation equal to each other: a = GM/R
2
. From this equation, scientists
were able to find the value of g on earth to be 9.81 m/s
2
.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '06
 RogerTobin
 Acceleration, Gravity, Mass, Gravitational constant, 1 mm, 1mm

Click to edit the document details