1
and they all fall Down!

• By Natalie Jones
• Presented 4/19/12

2
Glossary

• Slide 1 Title
• Slide 2 Glossary
• Slide 3 Question
• Slide 4 Hypothesis
• Slide 5 Materials
• Slide 6 Procedure
• Slide 7 Data- Trial 1
• Slide 8 Data- Trial 2
• Slide 9 Data- Trial 3
• Slide 10 Results
• Slide 11 Graph
• Slide 12 Photograph
• Slide 13 Conclusion
• Slide 14 Discussion
• Slide 15 Works Cited (applications/research
  included)
• Slide 16 Works Cited contd (applications/researc
  h included)
• Slide 17 Acknowledgments

3
Question

• How does the distance between dominoes affect the
  speed at which they fall?
• Independent Variable Distance between dominoes
• Dependant Variable The speed (cm/s) of the chain
• Controlled Variables Weight of dominoes,
  height/width of dominoes, length of chain, and
  surface underneath dominoes (friction).

4
Hypothesis

• It is my belief that the closer the dominoes are
  to each other, the faster the chain will be
  completed. I believe that this will occur because
  I think that the dominoes with less space in
  between them will pick up more momentum as they
  fall. Specifically, I think that the domino chain
  with 0.5 cm separating each domino will fall at
  the fastest speed.

5
Materials

• Dominoes (about 100)
• Stopwatch
• Ruler
• Masking tape
• Flat surface

6
Procedure

• 1.   Lay 1 meter of masking tape down on a flat
  surface to use as a reference for how long the
  domino chains should be.
• 2.   Line up the dominoes 0.5 cm apart from each
  other until they reach a distance of 1 meter.
• 3.   Time how long it takes for the dominoes to
  fall.
• Be sure to place yourself eye level with the
  chain of dominoes, as this is the easiest way to
  stop the timer exactly when the last domino
  falls.
• 4. Repeat steps 2-3 two more times for
  accuracy.
• 5. Repeat steps 2-4 with distances of 1.0 cm,
  1.5 cm, 2.0 cm, 2.5 cm, and 3.0 cm between the
  dominoes. Make sure that each domino chain lines
  up to be a constant distance of 1 meter.

7
Data- Trial 1
Space between dominoes (cm) Time taken for the chain to be completed (sec) Speed (cm/s)
0.5 0.93 107.53
1.0 1.02 98.04
1.5 1.11 90.09
2.0 1.23 81.30
2.5 1.36 73.53
3.0 1.47 68.02
8
Data- Trial 2
Space between dominoes (cm) Time taken for the chain to be completed (sec) Speed (cm/s)
0.5 0.92 108.69
1.0 1.04 96.15
1.5 1.13 88.49
2.0 1.23 81.30
2.5 1.36 74.63
3.0 1.47 68.97
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Data- Trial 3
Space between dominoes (cm) Time taken for the chain to be completed (sec) Speed (cm/s)
0.5 0.90 111.11
1.0 1.02 98.04
1.5 1.11 90.09
2.0 1.24 80.65
2.5 1.35 74.07
3.0 1.48 67.58
10
Results

• The data shows that speed and the distance
  between dominoes are inversely related that is,
  speed increased as the spacing between dominoes
  decreased. The domino chain where the dominoes
  were 0.5 cm apart had the fastest speed.

11
Graph
12
Photograph
13
Conclusion

• My hypothesis was proven correct by my
  experiment. I believed that the domino chain with
  0.5 cm separating each domino would fall at the
  fastest speed, and this prediction was supported
  by my data. It is my belief that the dominoes
  fell faster when they were closer together
  because more dominoes were able to fit into the
  meter-long chain, and the dominoes thus spent
  more time colliding with other dominoes,
  gathering force, than simply falling through air.
  This allowed the closer-spaced chains to gather
  more momentum than the farther-spaced chains,
  causing them to fall at a faster speed.

14
Discussion

• One problem I ran into during my project was how
  to accurately time the domino chains. At first, I
  would observe the chain from above and stop the
  timer when I heard the dominoes stop- relying
  mostly on my reflexes. However, this method
  produced scattered results, as that method wasnt
  reliable. I then decided to move the domino
  chains onto my kitchen counter, where I could
  bend down and observe the falling chains at eye
  level. Looking at the dominoes from the side
  rather than from above made it a lot easier see
  exactly when the last domino fell, and I relied
  less on reflex and more on conscious decision to
  stop the timer. This method gave me reliable
  results that made sense mathematically.

15
Works Cited (applications/research included)

• All Experts. N.p., n.d. Web. 4 Jan. 2012.
  lthttp//en.allexperts.com/?q/?Physics-1358/?domino
  -effect-1.htmgt.
• This website suggests that the reason why it
  takes longer for domino chains with longer
  distances between each domino to fall is because
  it takes a larger amount of time for the dominoes
  to rotate in their arcs towards the next domino.
  I also came to this conclusion in my project.
• The Domino Effect. Exploratorium. N.p., n.d.
  Web. 4 Jan. 2012. lthttp//www.exploratorium.edu/?t
  i/?human_body/?dominoeffect.htmlgt.
• This website uses dominoes to model nerve cell
  transmissions. This helped me understand some
  possible applications of my project in the real
  world of science, such as the study of neurology.
  
• How Fast Do dominoes Fall? . University of
  Tennesse at Martin. N.p., n.d. Web. 4 Jan. 2012.
  ltwww.utm.edu/?departments/?cece/?cesme/?psam/?PSAM
  /?psam15.pdfgt.
• This essay details an experiment similar to my
  own, but it tests the effects of spacing upon the
  acceleration of a domino chain. I used the
  conclusions from this paper to design my own
  experiment to test the effects of spacing upon
  the speed of a domino chain.

16
Works Cited contd (applications/ research
included)

• Larham, Ron. Validation of a Model of the Domino
  Effect. 19 Mar. 2008. Arxiv. Web. 4 Jan. 2012.
• This paper analyzes the current formula for
  determining the speed of a domino chain and comes
  to the conclusion that it is inaccurate, giving
  evidence that the formula has unaccounted-for
  limits. I used this papers formula to
  double-check my data, taking into account the
  variability of my experiment with a significance
  test.
• Leeuwen, J.M.J. Van. The Domino Effect. Leiden,
  The Netherlands InstituutLorentz, Leiden
  University (UP), 2004. Lorentz, Leiden
  University. Web. 4 Jan. 2012. ltwww.lorentz.leidenu
  niv.nl/?jmjvanl/?domino.pdfgt.
• This essay discusses the effects of friction
  upon the speed of a domino chain. This essay led
  me to understand that I had to control the
  friction of my domino chains, or else risk
  possible confounding of my results.

17
Acknowledgments

• Thanks to my amazing family for letting me use
  the kitchen counter for multiple hours during
  this project.
• Thanks to Mr. McClain for letting me borrow a
  calibrator.
• Thanks to the judges for allowing me to share my
  project.