Conservation of Momentum and Energy Lab 2014
Purpose:
To analyze momentum, energy, and the relationships between them.
Materials:
Air Track
Glider small (gold)
(2) Glider large (red)
Air supply
Vernier LabQuest
Vernier Photogate
Meter stick
Schematic Outline of Experiment: (NOT A PROCEDURE!!!)

Adjust the set screw on your air track to ensure that the track is level.
Momentum Analysis:

Setup LabQuest to measure velocity.
a.
b.
c.
d.
Connect photogate to Digital 1.
Verify Blocked/Unblocked
Select ‘Sensor’ then ‘Data Collection’ then set Photogate Mode to ‘Gate’.
Then enter the length of the object, in this case the index card that will be
blocking the photogate.
e. Then connect the second photogate to Digital 2 and repeat the setup process.
f. Then select the ‘table’ view of the data.

“Launch” the gliders into each other, and study what happens. How is the Labquest
gathering data, what does the data mean?

Create two scenarios where gliders can be collided together such that you can determine
the initial velocity and utilize the apparatus to find the final velocities of each glider.

“Crash” the gliders a few times until you have a modeled a good collision to gather data
from, then perform that good crash and gather your velocity data.

VERIFY YOUR INFORMATION WITH INSTRUCTOR!!!
Potential Energy vs. Kinetic Energy

For this portion you will only need to get the velocity of the red glider after a certain
distance has been travelled.

You will attach at least three different masses to the end of the string that hangs off the
pulley.

Hold the glider at an initial velocity of zero, and then release the glider. The force of
gravity acting on the mass will pull the glider towards the photogate. You should then
record the final velocity after the glider has travelled a specific distance. Do this for each
mass utilized.

You should record a final velocity of the cart, and a change in height of the mass. This
should be done for three different hanging masses.

VERIFY YOUR DATA WITH INSTRUCTOR!!!
Analysis:
In your final report all data gathered by you should be organized into a tabular form, and all
calculations supporting your work should be included.
1. Momentum – complete these steps for each collision scenario:
a. Using your initial velocities, determine what the momentum of the system was
before impact.
b. Using your final velocities, determine what the momentum of the system was
after impact.
c. Determine the percent error between your initial and final momentum.
d. Determine if the collisions you created were elastic, inelastic, or super-elastic and
numerically prove your conclusion.
e. Explain any energy gained or lost, or why the measured energy remained the
same.
2. Kinetic vs. Potential Energy – complete these steps for each mass used:
a. Diagram energy bar charts showing the system at rest, when the cart is halfway to
the photogate, and when it passes through the photogate.
b. Draw FBD’s of the system: the cart, the hanging mass, and how they relate to
each other.
c. Determine the change in Kinetic Energy of the system after it is released from
rest.
d. Determine the change in Potential Energy of the falling mass after it is released
from rest.
e. Determine the percent error between your Kinetic Energy of the system and the
Potential Energy of the falling mass.
LAB REPORT

Your lab report is due on TUESDAY 1/15/2014.

You will turn in an individual written lab report with the following sections: title, purpose /
objectives, apparatus, materials, procedure, data, analysis (CALCULATIONS and graphs
go in this section), and a conclusion.

Your Procedure will be very important. This should be a step by step process that includes
dimensional data and sketches so that your specific procedure can be replicated. Specifics
include details like: from what positions were the gliders launched, how long is the string,
which masses were used, where were the photogates positioned. This isn’t a complete list
of details, use your judgment. You can use the outline in this document as a starting point
– but it is NOT a complete procedure!

Your conclusion will explain how momentum and energy are conserved. You will also
need to explain your percent errors.

Typed lab reports are recommended.

See me if computer access is a problem for you.