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 1-6.
Submit your completed Pre-Lab Questions (page 2) per your faculty’s instructions.
Watch the Airtrack 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: Accelerated Motion
Lab format: This lab is a remote lab activity.
Relationship to theory (if appropriate): In this lab you will learn about motion of bodies under
the influence of constant acceleration.
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 – Electromagnet.
CONTENTS FOR THIS NANSLO LAB ACTIVITY:
Learning Objectives........................................................................................................
Background Information ...............................................................................................
Pre-lab Questions ..........................................................................................................
Equipment .....................................................................................................................
Preparing for this NANSLO Lab Activity .........................................................................
Experimental Procedure ...............................................................................................
Exercise 1: Calculating the Value of G ..........................................................................
Post-Exercise Questions ...............................................................................................
(Optional) Exercise 2: Initial Velocity ...........................................................................
(Optional) Exercise 3: Statistical Analysis ....................................................................
Creative Commons Licensing ........................................................................................
U.S. Department of Labor Information .........................................................................
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LEARNING OBJECTIVES:
After completing this laboratory experiment, you should be able to do the following things:
1. Determine experimentally the value of the local acceleration of gravity by determining
the relationship between position and time for an object free falling in the local
gravitational field.
2. Apply elementary statistics to arrive at the value of the constant free fall acceleration.
3. Determine the relationship between time and distance under constant acceleration.
4. Apply trigonometric relations to determine the local value of the acceleration of gravity.
5. Determine the percent error of the experimental result assuming the accepted value of
the local acceleration of gravity of 9.8 m/sec2 is correct.
BACKGROUND INFORMATION:
Our goal is to determine the relationship between the position and time for an object moving
with a constant acceleration. You can do this by simply noting the time for the object to reach
certain positions. 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 onedimensional version of the common air-hockey table, so the sled can only move in one
dimension.
Theory:
If an object's velocity changes with time, it is being accelerated. We are going to look at the
case where the acceleration is constant and causing the object to speed up. Acceleration is the
rate of change of velocity so a constant acceleration implies a constant rate of increase in
speed. This means that the equation for the velocity will be v = v0 + at, where a is the constant
acceleration and v is the velocity that increases with time. The position or the distance traveled
is more complicated than in the case of constant velocity, because as the objects speeds up, it
starts covering greater distances in equal amounts of time. The result is not a linear
relationship, but a power law relationship. If the initial velocity is zero, then the distance
traveled in the case of a constant acceleration obeys the following equation: d = v0t + 1/2 at2. In
our experiments, the initial velocity, v0, will be zero, so the equations will reduce to: v = at and
d = 1/2 at2.
PRE-LAB QUESTIONS:
1. Will a heavier sled have a faster velocity than the lighter sled? Why or why not?
2. Will a heavier sled accelerate more quickly than a lighter sled? Why or why not?
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3. Complete this sentence: A heavier sled will accelerate _________________ than a
lighter sled.
EQUIPMENT:
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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.
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.
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Summary of Experimental Procedure:
The approach to the determination of the value of the constant acceleration of the sled will be
to generate a statistically significant set of data, and calculate the mean of the sample
distribution. A total of ten "runs" will be made in which four discrete points in the linear path
will be recorded. The rows of data will be statistically analyzed. The values will be plotted to
determine the acceleration of the sled. Since the track is sloped, we will use the relationship
that a = g·sinθ (acceleration down the slope = [gravitational acceleration]sinθ) to determine
value of the local acceleration of gravity. We will repeat this process for sleds of different
masses to investigate the relationship between the acceleration of gravity and the mass of the
object being accelerated.
The timing data display consists of the eight numerical fields labeled "Photogate 1, 2, 3, 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.
200.0 cm
X cm
θ
Figure 1: Illustrative diagram (not to scale).
Remember that opposite/hypotenuse = sin θ
EXERCISE 1: Calculating the Value of G
In this exercise, you will calculate the value of the gravitational constant, g, which is equal to
9.80 m/s2 at sea-level. You will use sleds of different masses to do this and compare the results.
For all steps involving moving sleds, use the robot arm, if available, or ask the Lab Technician to
assist you.
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Data Collection:
1. Ask the Lab Technician to ensure that the launcher attachment is removed from the
electromagnet.
2. Using the robot arm (if available), or asking the Lab Technician to assist, place a sled
onto the electronic scale and determine the mass.
1. Ensure that the air pump is turned on, and place the sled onto the air track.
2. Click the gray “Click to Capture Sled” button to capture the sled with the electromagnet
on the left end of the air track (you may need to decline the track to bring the sled back
down to the electromagnet).
3. Incline the air track to between 4 and 10 cm.
4. Make sure Trial Number 1 is selected on the Controls tab, and click the green “Click to
Launch Sled” button.
5. Select the Data tab and make sure the data table fills in for Trial 1. Write down these
numbers to analyze at a later time.
6. Return to the Controls tab and increment the Trial Number so you don’t over-write your
previous data.
7. Repeat for trials 2 through 10 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.
8. Repeat this entire process for the other sled, which has a different mass.
9. 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):
1. Prepare a data table in Excel and enter all the times from your 10 runs of data.
2. Calculate the average of each time measurement, so you end up with just 8 data points
for each sled.
3. Calculate the instantaneous velocity of the sleds as they pass through each photogate.
4. Plot the four velocities you calculate (y-axis) vs. the time that it was half-way through
each photogate (x-axis). For example, if it entered the photogate at 1.0 seconds, and
exited at 1.14 seconds, then it was halfway through at 1.07 seconds. (NOTE: choose
Scatter Plot, and make sure that the column of times is to the left of the column of
velocities.)
5. Add a trend line to determine the value of the slope.
6. Use the angle relationship to determine the value of g from the value of the slope.
POST-EXERCISE QUESTIONS:
1. Are the values of g the same or different for the two different mass sleds?
2. What evidence do you have to support your conclusion?
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a. Are the values of the final velocity for each sled (measured at photogate 4) the same
or different?
3. What evidence do you have to support your conclusion?
a. Did the results of this experiment agree with your expectations or not? Explain.
(OPTIONAL) EXERCISE 2: Initial Velocity
Use the graphs you prepared in Exercise 1 to determine the initial velocity at time = 0.
1. What did you determine the initial velocity of each sled to be, based on the graphs?
2. Explain what this means, in terms of introduced error in your determination of the value
of g.
3. If the initial velocity of the sled was not zero, explain what you think could have caused
this to be the case.
(OPTIONAL) EXERCISE 3: Statistical Analysis
Calculate the value of g for each set of data so that you have 10 values of g for each sled.
Perform at t-test to determine if the average values are statistically different from each other.
1. Are the values of g statistically the same or different for the two different mass sleds?
(Support your answer with statistical calculations.)
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
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