lab 01 - Lab#1 Free-Fall Acceleration xxxxxx Physics 11...

Lab #1: Free-Fall Acceleration
xxxxxx
Physics 11
9/24/06
Introduction/Purpose
The purpose of this lab is to determine g, which is the acceleration due to gravity . Around
the earth the acceleration of a falling object is constant, so we should be able to determine
this value by dropping objects in free-fall. Average acceleration is defined as the change
in velocity divided by the change in time:
t
v
a
av
∆
∆
=
The change in velocity can be found by measuring the distance that the object travels in a
given time period. This equation is:
t
x
v
av
∆
∆
=
If the change in velocity can be found and the time measured, it would be possible to find
the value of acceleration.
Due to air resistance, however, this value of acceleration will be smaller than the actual
value. To account for this discrepancy we can use the principle of air resistance to
theoretically create a resistance-free movement. As the mass of the object increases, the
ability of the air to slow the object down decreases. Therefore, if the mass were infinite it
would overcome the force from the air resistance against it. The equation for the terminal
velocity of an object is:
d
t
aC
mg
v
ρ
2
=
As m increases towards infinity, the terminal velocity would also increase towards
infinity. This means that the air has no resisting effects on an object of this size. This idea
will come in handy when extrapolating from the recorded data in our experiment.
Experiment and Data
To begin to determine the value of g a weight will be dropped from above the ground.
Attached to the weight will be a piece of paper tape. At regular intervals, a machine will
make a mark on the paper as it passes through. By doing this, the change in the distance