The Domino Effect
Physics Lab Investigation
Introduction
Purpose
Through this lab investigation students will:
1. investigate the basics concepts of kinematics (position and speed)
2. determine if there is an “ideal spacing” that will maximize the speed of toppling dominoes
3. learn the importance of good lab techniques including:
reading lab instructions
following instructions
collecting quality data
communicating & collaborating with group members.
4. familiarize themselves with digital data analysis and graphing techniques as well as typing professional lab documents.
Background
A central property of motion is the idea of average speed – the (time) rate at which a distance is covered. It is important to note that average speed considers an extended distance and the entire time required to complete that distance. For a row of falling dominoes, the average speed of the falling row is determined by finding the ratio of the length of the entire row of dominoes to the time it takes them all to topple.
Through this investigation, we wish to determine if there is an “ideal spacing” to maximize the toppling of the dominoes. To compare dominoes of different sizes we need to standardize a unit of spacing – we will call this unit “domino units.” The spacing in domino units will express the spacing between the dominoes as a ratio to the height of the dominoes themselves. To determine the spacing in domino units:
1. Count the number of spaces between all of your dominoes.
2. The average spacing in centimeters.
3. The average spacing in domino units
Method
Materials
To complete this investigation each group of students will need the following items:
1 bag of dominoes stopwatches (1 for each group member) meterstick Vernier calipers
Safety and Equipment Notes
Although the equipment for this lab is inexpensive that does not mean that you can/should be careless with it. The dominoes are for experimental purposes; you are not to build structures with them or be playing any games. Do not throw any equipment.
Procedure
Before you begin, record the type of domino that you are using (the type of domino is written on the bag). Use the Vernier calipers to determine the height of the domino; your teacher will teach you how to use the calipers.
1. Use the meterstick to set up the dominoes in a straight row, with equal spacing between them. The dominos must be spaced at least the width of a domino apart.
2. Record all pertinent information and note any observations in a table similar to Table A.
3. When all timers are ready, count down and topple the row of dominoes. Record the time for the fall. Note – if the entire row does not topple the data for that particular trial is invalid. The trial must be redone.
4. Repeat steps 1-3 for four (more) different spacings; giving you a total of 5 trials.
If you are suspicious of the accuracy of ANY of your data, it is your responsibility to verify the data by redoing your trials.
Data Analysis - Take 2
1. Use Excel to create and complete a data table (similar to sample table A). Be sure to write equations (in the appropriate cells) that will complete the necessary calculations for you (that is the benefit of a spreadsheet).
2. Use Excel to create a graph for YOUR data. Plot the average speed (cm/s) versus the spacing in domino units. You will create an x-y scatter plot with data points shown.
3. Using your graph determine the best regression (linear, exponential, etc.). Include the trend line and the equation for your line/curve and the r2 value near your graph. NOTE - A linear regression may not be the best fit for the data. Visit this link if you need help on finding the regression in excel. Visit this link of you need help finding the regression line in google sheets. 4. Import your data to the appropriate Google Doc for this lab.
Copy and paste the following link to add in your data: https://docs.google.com/spreadsheets/d/1ZxAdypbB1kRLPZz2495DFFm1AezE2MO5nX7ZwqbHzc8/edit?usp=sharing
Once all student data has been imported, use google sheets or excel to create a graph for all of the student data for YOUR domino type. Plot the average speed (cm/s) versus the spacing in domino units.
5. Using the class-data graph, determine the best regression (linear, exponential, etc.). Include the trend line and the equation for your line/curve and the r2 value near your graph.
NOTE - A linear regression may not be the best fit for the data. Visit the "resources" portion of the physics website for help on finding the regression.
TYPED Write Up - Each GROUP is responsible for submitting the following:
1) Introduction Section à This section includes a statement of the purpose of the lab, and details on the lab equipment.
2) Data Section à this includes the filled in sample data table, sample calculations for each unique equation used, graph (for your group's data) from EVERY MEMBER of the group.* It should also include ONE graph created using the class-data from the google doc. For your groups specific type of domino (wood or plastic)
3) Typed Lab Questions (you must include the question in bold and the answer un-bolded)
4) Conclusions paragraph
* Why every member? We will be using Excel A LOT in this class. This is a skill that everyone must practice so that everyone can master the basics of the program. This is to verify that every member of the group participated in this practice.
Other helpful Links
How to read a metric Vernier caliper (you tube)
How to read a Vernier caliper (word document) VERNIER CALIPERS
Testing yourself on reading a Vernier caliper
Adding a regression line in google
Write Up
This lab investigation requires a formal – typed report. You will be graded based on the following Rubric.
General organization
Paper is typed / 0
Not typed / 1
Typed or all procedural direction followed / 2
Only parts of paper are typed and all procedural direction followed / 3
Minor errors in procedure but paper is all typed / 4
Typed and all procedural direction followed
Title Information
Lab Tittles
Teacher name
Class Period
Due date
Student Names / Not done / Missing information or not formatted properly / All information provided appropriately / X / X
Pertinent Information
Domino type
Domino Length /
Not done /
Missing information /
All information provided /
X /
X
Sample Calculations
Sample for each unique equation or data column /
Not done /
Missing information /
All information provided /
X /
X
Data Table
completed table for individual group data
Includes all labels, units and appropriate title / Not done / Missing information
-
Calculations incorrect / Calculation incorrect
or
missing info / Calculation correct
and
all info is present / X
Graph 1
completed graph for individual group data
Includes all labels, units and appropriate title
Size does matter
*you will be graded individually for this portion of the lab / Not done / Missing information
-
Graphed incorrectly
-
too small / X / Completed correctly with appropriate labels and general title
-
Inappropriate size graph / Completed correctly with appropriate labels and informative title
good size graph
Graph 2
completed graph for total student data
Includes all labels, units and appropriate title
Includes R2value and equation
Size matters / Not done / Missing major information
-
Graphed incorrectly
-
too small / Minor missing information but has graph completed correctly
-
Inappropriate size graph / Completed correctly with appropriate labels and general title
-
Inappropriate size graph / Completed correctly with appropriate labels and informative title, R2value and equation
good size graph
Conclusion
Answer to lab procedure question / Not mentioned / Did not correctly identified the correct spacing that will produce the fastest toppling time / Is vague about correctly identified the correct spacing that will produce the fastest toppling time / Correctly identified the correct spacing that will produce the fastest toppling time
Conclusion
Sources of error and summarization of lab / Not done / Lists human errors and discussion is poor / Lists human error or discussion is mediocre / Avoids human errors and discussion is decent / Avoids human error and provides a good discussion
Follow up
(each question) / 0 / 1 / 2
Questions stated and answered accurately and appropriately. / Not done , incorrect or
Vague AND did not include question / Vague response
or did not include question / Included question and responded accurately and with sufficient detail
Name ______Period 1 2 3 4 5 6 7 8 Domino Lab Follow Up
Introduction Section:
Statement of purpose
Type of dominos used ______Domino length ______
Data Section:
Table A – Sample Data Table
Trial / Row Length (cm) / Average Spacing(cm) / Average Spacing (domino units) / Average toppling time (s) / Average speed
(cm/s) / Observations
1
5
Sample of each separate/unique Calculation: (you may print this section out and hand write this section)
Using the gathered data from all physics’ classes, create a graph of YOUR domino type. Copy and paste the graph below (remember each group member must create their own graph of your groups’ data and attach to this lab)
General Lab Questions:
1. Your group collected data on two separate days. Unfortunately you didn’t use the same bag of dominos (you kept the material constant though). You are positive that the two bags have different total amounts of dominos. Your teacher told your group not to worry about that because ………..
2. What is the definition of average speed?
3. Why do we calculate the average speed of the falling dominoes rather than the instantaneous speed?
Questions about YOUR data/lab questions:
4. Which type of regression best fit YOUR data for the wood (or plastic…depending on which domino set you used) dominos?
5. Based on only YOUR data, what spacing (in domino units) would you predict to give the fastest toppling speed for the wood (or plastic…depending on which domino set you used) dominos?
6. What is the problem with making this conclusion based only on YOUR data?
Questions about CLASS data/lab questions:
7. Which type of regression best fit the entire class data for your specific domino type? In other words, what is the general trend of the data (linear, polynomial, exponential, etc.)?
8. Based on all student domino data, what spacing (in domino units) would you predict to give the fastest toppling speed for the wood (or plastic…depending on which domino set you used) dominos?
9. Your friend wants to maximize his domino toppling speed and asks you to help him since you have collected and analyzed data on the topic. He asked" should I place my dominoes close together, far apart or some other spacing." What would be your response and why?
10. Now, compare the trend of the data for both types of dominoes. Is the maximum speed spacing the same for the different domino types?
Conclusions: (you can delete the directions below and type your conclusion in the space)
Write a paragraph (or more) that concludes your results for this extension of the lab. Be sure to include the spacing (in domino units) would give the fastest toppling speed for the dominos and the potential problems with your prediction for the ideal spacing. Give a logical reason why the recognized spacing produced the fastest toppling time. You should discuss any differences in your data compared to the class data. You should also discuss the difference between the wood and plastic dominoes (if need be…you can consult with a group that analyzed the other type of domino). You also need to discuss possible errors for this investigation. Human error cannot count as a possible source of error. Human error is anything change that could have been realistically made to alter the results of the lab. For example, a source of error cannot be that someone measured wrong……that should have been corrected while completing the lab.