1. Designing Seismometers
Nikki Moriarty
Horace Mann Middle School
Abstract
Project Description
Assessment of Project
You are a group of engineers who have been given the challenge of designing a reliable seismograph to be used to record earthquake activity by villages in impoverished areas. You have noticed that the current seismometer accessible by the village is not designed correctly. Your job is to redesign a more accurate seismograph by either adjusting the current machine or building a new machine from scratch.
Your machine must be able to record motion visually on a scale of your own design. The machine which is able to record the smallest disturbance will be considered the best design. In the event of a tie, the best design will be the machine that uses the least amount of material and records the smallest disturbance.
Constraints:
You may bring materials from home with your boss’s (Mrs. Moriarty) approval. Anything brought from home must be easily accessible by all. Remember this is for impoverished areas.
You must keep track of all materials used.
You may modify the existing machine.
You may build a new one from scratch.
Students constructed a device with the goal of being able to detect vibrations from a rubber ball being dropped onto a science table. Students were provided with materials that they could use, as well as the ability to bring in objects with prior approval. Students were required to do all work within the classroom setting and could either build from scratch, or modify a previously tested, existing model used by the entire class. Students were required to draw and describe an initial design, keep track of all materials used and changes made, and be able to explain why those changes were necessary
Evaluation: Your seismometer will be tested by conducting three trials. The trials will consist of dropping a rubber ball onto the table from 3 distinct heights (0.5m, 1.0m, & 1.5m)
Students were given a handout on which they were required to record all steps of their design process.
WV NxGen Standards purpose
Projects were assessed informally through conversations with groups during the engineering process. At the end of the project, students were assessed using a rubric and their document.
Engineering Design Products
S.6-8.ETS.2- evaluate competing design solutions using a systematic process to determine how well they meet the criteria and constraints of the problem.
S.6-8.ETS.3- analyze data from tests to determine similarities and differences among several design solutions to identify the best characteristics of each that can be combined into a new solution to better meet the criteria for success.
S.HS.ETS.2 – design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering.
Left: Team Team’s initial design for their seismometer.
Right: Team Team building their second design. Attempting to create a mote stable base after their initial design toppled over during testing.
Project Timeline
Evaluate/Reflect
45 minute class period: meets M-F
Day 1: Whole class Seismometer Lab
Day 2: Initial design of individual group machines
Day 3 & 4: Build of initial design
Day 5: Test of all designs
Day 6: Redesign and rebuild
Day 7: Rebuild
Day 8: Re-test
Day 9: Unit test
Overall, I think the project exceeded expectations. I was very nervous about completing this project because neither my students nor I had much experience with engineering design. I’m not entirely sure the students consistently used scientific reasons for their designs and changes, so that is something I need to be more cognizant of in the future. Students’ scores on the post-test seismometer questions improved compared to the pre-test. For future iterations of this project, I need to either find a table that will shake easier, or a material to drop on the lab tables that will cause more vibrations.
Above: Teams working on their projects.
Left: Various initial designs prior to first test phase. The least successful designs tended to be those who attempted to modify the pre-existing prototype. Most successful were designs that utilized a pen hanging from a string.
Right: Only modified design that successfully registered all three test vibrations. Second design. Also only group to not build their own machine in the second trial.
Acknowledgements
Thank you to:
Earth Science Parents for donating supplies
Holly Cain
Megan Bradfield
Samantha Blair
Dr. Deb Hemler
ESS Passport Cohort 2
Mrs. Shandon Tweedy, HMMS Principal
Kanawha County BOE
Sources
Modified from:
* tryengineering.org - Seismograph project
* NASA TPS Design Specifications and Test Results Sheet.