Part 1 - Get a Lab Appointment and Install Software:
Set up an Account on the Scheduler (FIRST TIME USING NANSLO):
Find the email from your instructor with the URL (link) to sign up at the scheduler.
Set up your scheduling system account and schedule your lab appointment.
NOTE: You cannot make an appointment until two weeks prior to the start date of this lab assignment.
You can get your username and password from your email to schedule within this time frame.
Install the Citrix software: – go to http://receiver.citrix.com and click
download > accept > run > install (FIRST TIME USING NANSLO).
You only have to do this ONCE. Do NOT open it after installing. It will work automatically when you go
to your lab. (more info at
http://www.wiche.edu/info/nanslo/creative_science/Installing_Citrix_Receiver_Program.pdf)
Scheduling Additional Lab Appointments:
Get your scheduler account username and password from your email.
Go to the URL (link) given to you by your instructor and set up your appointment.
(more info at http://www.wiche.edu/nanslo/creative-science-solutions/students-scheduling-labs)
Changing Your Scheduled Lab Appointment:
Get your scheduler account username and password from your email. Go to http://scheduler.nanslo.org
and select the “I am a student” button. Log in to go to the student dashboard and modify your
appointment time. (more info at http://www.wiche.edu/nanslo/creative-science-solutions/studentsscheduling-labs)
Part 2 – Before Lab Day:
Read your lab experiment background and procedure below, pages 1-8.
Submit your completed Pre-Lab Questions (page 3) per your faculty’s instructions.
Watch the Air Track Control Panel Video Tutorial
http://www.wiche.edu/nanslo/lab-tutorials#airtrack
Part 3 – Lab Day
Log in to your lab session – 2 options:
1)Retrieve your email from the scheduler with your appointment info or
2) Log in to the student dashboard and join your session by going to http://scheduler.nanslo.org
NOTE: You cannot log in to your session before the date and start time of your appointment. Use
Internet Explorer or Firefox.
Click on the yellow button on the bottom of the screen and follow the instructions to talk to your lab
partners and the lab tech.
Remote Lab Activity
SUBJECT SEMESTER: ____________
TITLE OF LAB: Conservation of Momentum and Energy
Lab format: This lab is a remote lab activity.
Relationship to theory (if appropriate): In this lab you will learn about conservation of energy
and momentum.
Instructions for Instructors: This protocol is written under an open source CC BY license. You
may use the procedure as is or modify as necessary for your class. Be sure to let your students
know if they should complete optional exercises in this lab procedure as lab technicians will not
know if you want your students to complete optional exercises.
Instructions for Students: Read the complete laboratory procedure before coming to lab.
Under the experimental sections, complete all pre-lab materials before logging on to the
remote lab. Complete data collection sections during your online period, and answer questions
in analysis sections after your online period. Your instructor will let you know if you are
required to complete any optional exercises in this lab.
Remote Resources: Primary – Air Track; Secondary – Launcher.
CONTENTS FOR THIS NANSLO LAB ACTIVITY:
Learning Objectives........................................................................................................
Background Information ...............................................................................................
Pre-lab Questions ..........................................................................................................
Equipment .....................................................................................................................
Preparing for this NANSLO Lab Activity .........................................................................
Experimental Procedure ...............................................................................................
Exercise 1: Kinetic Energy and Momentum in an Inelastic Collision ...........................
Post-Exercise Questions ...............................................................................................
(Optional) Exercise 2: Statistical Analysis ....................................................................
Creative Commons Licensing ........................................................................................
U.S. Department of Labor Information .........................................................................
1|Page
Last Updated January 29, 2015
2
2
3
3
3-4
4-6
6-7
7
7
8
8
LEARNING OBJECTIVES:
After completing this laboratory experiment, you should be able to do the following things:
1. Measure the velocity of an object before and after a collision.
2. Determine the relationship between the momentum and kinetic energy of an object
before and after an inelastic collision.
3. Determine whether kinetic energy and/or momentum are conserved during an inelastic
collision.
BACKGROUND INFORMATION:
Our goal is to determine the relationship between the kinetic energy and momentum of two
objects before and after an inelastic collision. To remove friction, you will use an air track,
which is a linear track that has many holes through which air blows, suspending a sliding cart or
sled. The sled moves along on a layer of air and does not actually touch the underlying track.
The air track is a one-dimensional version of the common air hockey table, so the sled can only
move in one dimension.
Theory:
Conservation of linear momentum and energy are examined in this lab. Conservation laws are
among the most important parts of physics. By definition, the value of a conserved quantity
before a physical process begins is the same as the value of the conserved quantity after the
process has occurred. Any physical process brings something from an initial state to a final
state, and the final state can be quite different from the initial. The conservation laws give us a
way of comparing these two states. That is the root of their importance in physics.
The conservation of linear momentum of an isolated system is a core law of physics. The total
momentum of a system before a collision is always equal to the final total momentum, since
the system of colliding objects can be considered as isolated during the collision. External
influences are negligible compared to the strength of the interaction between the colliding
bodies during the collision, and the short duration of the collision.
You will examine inelastic collisions in this lab activity. Elastic collisions conserve the kinetic
energy of the system as well as momentum. A completely (or perfectly) inelastic collision, in
which the two objects stick together, is a special case that will be considered. The kinetic
energy of the system is not conserved during an inelastic collision.
2|Page
Last Updated January 29, 2015
PRE-LAB QUESTIONS:
1. The combined sleds after the collision will have a velocity that is
2.
3.
4.
5.
______________________ than the single moving sled before the collision. Explain why
this is so.
The combined sleds after the collision will have a momentum that is
______________________ than the single moving sled before the collision. Explain
why this is so.
The combined sleds after the collision will have a kinetic energy that is
______________________ than the single moving sled before the collision. Explain
why this is so.
A more massive sled combination (after the collision) will have a _______________
(faster/slower) final velocity than a less massive sled combination. Explain why this is so
A more massive sled combination (after the collision) will have a _______________
(higher/lower) final kinetic energy than a less massive sled combination. Explain why
this is so
EQUIPMENT:
1.
2.
3.
Paper
Pencil/pen
Computer with Internet access (for the remote laboratory and for data analysis)
PREPARING FOR THIS NANSLO LAB ACTIVITY:
Read and understand the information below before you proceed with the lab!
Scheduling an Appointment Using the NANSLO Scheduling System
Your instructor has reserved a block of time through the NANSLO Scheduling System for you to
complete this activity. For more information on how to set up a time to access this NANSLO lab
activity, see www.wiche.edu/nanslo/scheduling-software.
Students Accessing a NANSLO Lab Activity for the First Time
For those accessing a NANSLO laboratory for the first time, you may need to install software on
your computer to access the NANSLO lab activity. Use this link for detailed instructions on
steps to complete prior to accessing your assigned NANSLO lab activity –
www.wiche.edu/nanslo/lab-tutorials.
3|Page
Last Updated January 29, 2015
Video Tutorial for RWSL: A short video demonstrating how to use the Remote Web-based
Science Lab (RWSL) control panel for the air track can be viewed at
http://www.wiche.edu/nanslo/lab-tutorials#airtrack.
NOTE: Disregard the conference number in this video tutorial.
AS SOON AS YOU CONNECT TO THE RWSL CONTROL PANEL: Click on the yellow button at the
bottom of the screen (you may need to scroll down to see it). Follow the directions on the pop
up window to join the voice conference and talk to your group and the Lab Technician.
EXPERIMENTAL PROCEDURE:
Read and understand these instructions BEFORE starting the actual lab procedure and collecting
data. Feel free to “play around” a little bit and explore the capabilities of the equipment before
you start the actual procedure.
Summary of Experimental Procedure:
We will set up the experiment with one sled positioned at rest in the middle of the air track and
one attached to an electromagnetic launcher device on the left end of the air track. The sled on
the launcher will have a device with a wax cylinder, and the other one will have a device with a
needle on it that will cause the two sleds to stick together when they collide, as shown in the
two images below.
4|Page
Last Updated January 29, 2015
Figure 1: Photo of Air Track
wax cylinder and the device
with a needle on it.
Figure 2: Close up of the wax
cylinder and the device with a
needle on it.
Photogates 1 and 2 will be used to measure the velocity of the sled that is launched, and
photogates 3 and 4 will be used to measure the velocity of the two sleds after the collision.
Instantaneous Velocity Values:
The timing data display (Figure 3) consists of the eight numerical fields labeled "Photogate 1, 2,
3, and 4". The first number is the time value in seconds that has elapsed since the sled was
launched and the leading edge of the flag mounted on the sled coincided with the
prepositioned photogate. The second value is the time in seconds that has elapsed since the
leading edge of the flag initiated the signal and the trailing edge interrupted the signal. Thus,
the time between these two values is how long it takes the flag on the sled (length = 10.0 cm)
to pass through one photogate. This way, we can measure the instantaneous velocity as the
sled passes through each photogate.
5|Page
Last Updated January 29, 2015
Figure 3: RWSL Air Track Control Panel “Data” Tab.
EXERCISE 1: Kinetic Energy and Momentum in an Inelastic Collision
For all steps involving moving sleds, use the robot arm, if available, or ask the Lab Technician to
assist you.
Data Collection:
1. Ask the Lab Technician to ensure that the launcher attachment is installed on the
electromagnet.
2. Using the robot arm (if available), or asking the Lab Technician to assist, place each sled
onto the electronic scale and determine the mass.
3. Ensure that the air pump is turned on, and place the sled with the needle in the middle
of the air track.
4. Click the gray “Click to Capture Sled” button to energize the electromagnet.
5. Place the other sled onto the air track and load it onto the launcher.
6. Make sure Trial Number 1 is selected on the Controls tab, and click the green “Click to
Launch Sled” button.
7. Select the “Data” tab on the RWSL control panel and make sure the data table fills in for
Trial 1. Write down these numbers to analyze at a later time.
6|Page
Last Updated January 29, 2015
8. Return to the “Controls” tab on the RWSL control panel and increment the Trial Number
so you don’t over-write your previous data.
9. Repeat steps 3 through 8 to get a total of ten runs. Rotate control of the control panel
to allow each student in your group to collect at least one set of data. You can collect
more data than this if you want to and have time.
10. Repeat the process to collect 10 runs using a more massive sled.
11. Record all data in an appropriate table in your notebook or on your computer.
Analysis (can be done after your lab period if you run out of time):
12. Prepare a data table in Excel and enter all the times from your 10 runs of data.
13. Remember that photogates 1 and 2 are for the launched sled, and photogates 3 and 4
are for the combined sleds after the inelastic collision.
14. From your ten data sets, calculate the average velocity of the single sled before the
collision, and the average velocity of the combined sleds after the collision.
15. Use the masses and velocities you determined to calculate the momentum and energy
of the sleds before and after the collision.
16. Record all your data in an appropriate table.
POST-EXERCISE QUESTIONS:
1. How did the velocity of the combined sleds compare with the velocity of the single sled?
2. Was momentum conserved in the collision?
a. What evidence supports your conclusion?
3. Was kinetic energy conserved in the collision?
a. What evidence supports your conclusion?
4. Did the results of this experiment agree with your expectations or not? Explain.
(OPTIONAL) EXERCISE 2: Statistical Analysis
Calculate the velocity of the single and combined sleds for each of the 10 data sets.
1. Was the velocity of the combined sleds statistically the same or different than the
velocity of the single sled? (Present statistical calculations to support your answer.)
2. Quantify the experimental error in the average velocity for the single sled and for the
combined sleds. (Present statistical calculations to support your answer.)
7|Page
Last Updated January 29, 2015
For more information about NANSLO, visit www.wiche.edu/nanslo.
All material produced subject to:
Creative Commons Attribution 3.0 United States License 3
This product was funded by a grant awarded by the U.S.
Department of Labor’s Employment and Training Administration.
The product was created by the grantee and does not necessarily
reflect the official position of the U.S. Department of Labor. The
Department of Labor makes no guarantees, warranties, or
assurances of any kind, express or implied, with respect to such
information, including any information on linked sites and
including, but not limited to, accuracy of the information or its
completeness, timeliness, usefulness, adequacy, continued
availability, or ownership.
8|Page
Last Updated January 29, 2015