Dependent Variable: Velocity of wave (wave velocity) Constants: Plastic storage container Piece of wood Height from which the wood is dropped and the way it is held before each time it is dropped Gravel-like substance that creates an uneven bottom—this includes both its physical material and the amount of it that is placed on the bottom of the tank during each treatment Time at which the stopwatch is started after the wooden block is dropped and a wave is created Problem: It is a known fact about tsunamis that if the level of the water is higher, then the velocity of the wave will be greater.
How does an uneven bottom affect the velocity of tsunami waves at different water levels? Hypothesis: I believe that an uneven bottom will still result in the velocity of the wave being greater when the water level is higher. 5 MLA References with Annotations: 1. Michelle, Maranowski, PhD. “The Science Behind Tsunamis: Study the Effect of Water Depth on Wave Velocity. ” Science Buddies. Science Buddies, 2005-2012. Web. 13 Sept 2012. http://www. sciencebuddies. org/science-fair-projects/project_ideas/OceanSci_p014. html#background •This electronic source inspired my project idea, and provided me with the materials and procedure that I would need to execute my project. In addition, it helped me understand exactly what the original project would be testing, and also how I could make it my own. 2. “What are Tsunamis? ” CBC News. Canadian Broadcasting Corporation/Radio Canada, 29 Sept 2009. Web. 13 Sept 2012. http://www. cbc. ca/news/world/story/2009/09/29/f-tsunami-forces-of-nature. html •This electronic source provided me with basic tsunami information.
I believe that it is important to have as much information as possible about my topic, so that I am able to get the most out of my project and understand it to the fullest. 3. “Tsunamis. ” National Geographic. National Geographic Society, 1996-2012. Web. 13 Sept 2012. http://environment. nationalgeographic. com/environment/natural-disasters/tsuna mi-profile/ •This electronic source was helpful to me by providing me with even more background information on tsunamis and their effects. In addition, a video on National Geographic allowed me to view a real tsunami in action. 4.
This is an important thing to note, because it helps put into perspective how a tsunami is not only devastating once it hits shore, but also before it hits shore and is still a violent wave uncontrollably speeding across the ocean toward the shore, destroying almost everything in its path. Materials: 1. Plastic storage box (at least 40 cm long x 5 cm deep) 2. Source of water 3. Small gravel or pebbles (to be spread over bottom of storage box as representation of an uneven bottom in the ocean) 4. Piece of wood (2 in thick x 4 in wide x 8 in long) 5. Sharpie permanent marker 6. Metric ruler 7. Digital stopwatch . Bright ceiling light (above location of experiment) 9. Hand towel 10. Volunteer to run stopwatch 11. Lab notebook 12. Graph Paper Procedure: 1. Find a well-lit location at which to execute experiment (favorably indoors and free of commotion) 2. Remove any items away from location that could be damaged by potential splashing water from storage box 3. Place storage box on white sheet and under bright ceiling light with no surrounding lights in order to see waves as clearly as possible 4. Cover bottom of storage box with layer(s) of gravel/pebbles as needed until bottom of box cannot be seen 5.
Fill storage box with a few centimeters (cm) of water 6. Draw small line with sharpie on a shorter end of the box’s exterior, approximately 2. 5 cm below rim of box (this marks the spot from where piece of wood will be dropped) 7. Begin practicing making and tracking waves 8. Line up bottom of wood at marked line and drop, immediately thereafter watching for resulting wave traveling from one end of tank to the other 9. Begin executing real experiment once comfortable creating and tracking waves 10. Empty/fill water tank after practice runs until 1 cm of water is left in tank. Use metric ruler for accuracy.
This water depth will be used as the measurement for the first treatment 11. Create appropriate data table in lab notebook 12. Notify volunteer with stopwatch when they should start and stop timing the wave’s path (those times should be as soon as wooden block is dropped and wave is formed, and as soon as wave returns and hits other end of box) 13. Record the time in data table from lab notebook 14. Repeat step 11 nine more times (nine more tests), always waiting for water to settle before dropping wood again from consistent position each test 15. Fill box with water depth 2 cm (confirm with ruler) 16. Repeat steps 11-13 17.
Fill box with water depth of 3 cm (confirm with ruler) 18. Repeat steps 11-13 19. Empty box and repeat steps 9-16 four times so that end result is 5 trials (10 tests per trial) for each of the 3 depths 20. Analyze data for each water depth for each trial across the 10 tests and record data in notebook 21. Average time data across the three trials from the numbers calculated in step 19 22. Measure and record distance between where wave was created (leading edge of mark from where wood was dropped) and other end of box 23. Divide distance by average time it took for wave to move from one end of tank to the other for each water depth.
The answer recorded in notebook will be wave velocity 24. Plot data (x-axis=water depth, y-axis=wave velocity) 25. Answer the following questions: •What is the relationship between the water depth and the wave velocity? •Is it a linear relationship? •Does the wave velocity increase or decrease with increasing water depth even with an uneven bottom? •Does this result make sense to you according to the research that you have done on tsunamis that seems to state that, in general, if the level of the water is higher then the velocity of the wave will be greater? If it does not match, then the conclusion should be that an uneven bottom does affect the velocity of tsunami waves. 26. Equation 1, below, shows the mathematical relationship between the wave velocity in shallow water as a function of water depth. Equation 1 states that velocity is the square root of the product of the acceleration of gravity and the water depth: V = vgd V = Velocity in meters/second (m/s) g = Acceleration of gravity (9. 8 meters/second2) d = Water depth in meters (m) 27. Using equation 1, plot wave velocity as a function of water depth. How does the plot compare to results from the storage box/model-tsunami?