1. Simple/Compound Machines
Johnathan Tran
San Diego Science Olympiad Workshop

2. San Diego Science Olympiad Workshop - 2019
Event Overview
Team of two in a hybrid knowledge/build event
Written Test
Concepts based on simple machines (and compound machines for Division C)
Competitors will have at least 20 minutes
Device Test
3 unknown masses – A, B, C
Calculate ratio of A/B, B/C using lever (two levers for Division C)
San Diego Science Olympiad Workshop

3. San Diego Science Olympiad Workshop - 2019
Impound
Impounding: set aside device, diagram, and graphs before any blocks begin
Prevents competitors from modifying their devices/graphs and thus gaining unfair advantage over other teams
Binder, writing utensils, calculators, anything unrelated to the device is NOT impounded
Missing impound will result in device testing scores (time score, ratio scores) multiplied by 0.7 and a chart score of 0
San Diego Science Olympiad Workshop

4. San Diego Science Olympiad Workshop - 2019
Allowed Materials
One 3-ring binder of notes: any size, any notes as long as everything is secured within the rings prior to test
Two stand-alone calculators allowed of any type
Various tools/supplies ex: ruler, protractor, writing utensils
These do NOT need to be impounded
San Diego Science Olympiad Workshop

5. San Diego Science Olympiad Workshop - 2019
Written Test Material
At least 3 conceptual questions e.g. types and terminology
Div B: simple machines only
Div C: simple and compound machines
At least 3 calculation questions:
Div B: ideal and actual mechanical advantage, efficiency, load, and effort
Div C: any of the above plus compound machines, potential and kinetic energy, coefficient of friction
San Diego Science Olympiad Workshop

6. Written Test Material cont.
Questions will be about these simple machines (and combinations in Division C) in static equilibrium only:
Lever (all three types)
Inclined plane
Wedge
Wheel and axle (includes gears)
Pulleys
Screws (Division C)
Photo courtesy of Wikimedia Commons
San Diego Science Olympiad Workshop

7. San Diego Science Olympiad Workshop - 2019
Levers
From top to bottom: 1st class, 2nd class, 3rd class
Based on position of fulcrum, effort, load in relation to each other
Photo courtesy of Wikimedia Commons
San Diego Science Olympiad Workshop

8. San Diego Science Olympiad Workshop - 2019
Device Testing
3 unknown masses, each between 20.0 g and g with flexible loop larger enough to fit a golf ball
Mass with fully stretched out loop less than 15.0 cm x 15.0 cm x 20.0 cm
Calculate ratio of A/B (ratio 1) and B/C (ratio 2) using lever(s)
San Diego Science Olympiad Workshop

9. San Diego Science Olympiad Workshop - 2019
Division B Lever
First class lever: single beam no longer than 80.0 cm
From equation of lever, we can calculate M1/M2 = b/a
Photo courtesy of Creative Commons
San Diego Science Olympiad Workshop

10. San Diego Science Olympiad Workshop - 2019
Division C Lever
1st class lever in series with 2nd or 3rd class
Each beam no greater than cm
Mechanical advantage of first multiplied by advantage of second to find ratio of larger mass to smaller
Photo courtesy of Southern California SO Workshop 2019
San Diego Science Olympiad Workshop

11. San Diego Science Olympiad Workshop - 2019
Device Preparation
Must fit inside cm x cm x 50.0 cm box at impound
Can be larger during actual device testing
Any materials except electric components or springs
Accommodate masses: make sure device has 20.0 cm of clearance for masses, can hold loop
San Diego Science Olympiad Workshop

12. San Diego Science Olympiad Workshop - 2019
Device Testing
Eye protection type B required
Any valid tools brought into testing can be used: graphs, calculators, protractors
5 minutes at start of block allowed for set up and calibration
Teams called individually for testing anytime during block
Timing starts when masses are given to team: max of 4 minutes
Timing stops when team gives Event Supervisor the calculated ratios or 4 minutes elapses
San Diego Science Olympiad Workshop

13. San Diego Science Olympiad Workshop - 2019
Device Testing
Masses can not be modified
Teams must use physics of lever to calculate mass
Can only adjust position of masses and/or fulcrum
Can use either 2 or 3 of the classes at once
No external masses unless fixed in place before impound: cannot be moved during event
Teams with no device or do not make honest attempt to use device receive ratio scores and time score of 0
San Diego Science Olympiad Workshop

14. San Diego Science Olympiad Workshop - 2019
Chart Score (10 points)
Teams must prepare graphs/table showing relation between masses and device parameters e.g. distances from fulcrum: up to 8 points
At least 4 distinct graphs/tables for 0.5 points each (2 points max)
One of the graphs/tables chosen for
2 points for data spanning the possible mass range
2 points for having at least 10 data points in each data series
2 points for proper labeling e.g. title, team name, units
Labeled device diagram: 2 points
San Diego Science Olympiad Workshop

15. Scoring (100 points total)
10 points for Chart Score
45 points for Exam Score: (Written Test score / Highest Written Test score) x 45
15 points for Time Score: (240 – device testing time in seconds) / 240 x 15
15 points for each Ratio Score: (1 – (abs(actual – measured) / actual)) x 15
Ratio 1: A/B Ratio 2: B/C
San Diego Science Olympiad Workshop

16. San Diego Science Olympiad Workshop - 2019
Tips
Can use programmable calculator
Try out different device designs
Practice with non-integer ratio of masses
San Diego Science Olympiad Workshop