2018 Physics Olympics

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Physics Goes Boom

Overview

The WKU Department of Physics & Astronomy detonates another round of the Western Kentucky Physics Olympics on Saturday, 24 February 2018. Teams of four high school students are invited to compete in this half-day competition consisting of a pentathlon of challenging problem-solving activities that reward teamwork, communication and creativity.

The 2018 Physics Olympics competition will commence with two activities that involve competitors arriving at the event ready to compete with devices they have designed, constructed, and tested. For the Bomb Shelter event, teams will compete to test the four protective shelters they designed and constructed to keep an egg safe from a dropped baseball. For the Bomb Disposal Manipulator Arm event, each team constructs from plastic soda straws and sewing pins the longest possible arm to support a mass. The "Calculation / Communication Challenge" will require each team to divide into pairs, with one pair creating a solution for an explosive problem, and the other pair following the directions to perform the experiment. The "Impromptu Team Activity" and "Order-of-Magnitude Quiz" will remain cloaked in secrecy until the day of the event.

 

Do-Ahead Event: Bomb Shelter

Goal:

Using only toothpicks and glue, build the least tall, lowest mass shelter which will protect an egg from a dropped baseball.

Design and Construction Procedure:

1. Each team will bring to the competition four shelters for testing.
2. The shelters must be between less than 30.0-cm tall at its tallest. Each shelter must be able to be placed on top of a grade-A large chicken egg (provided by organizers) while the egg placed onto the floor. The egg cannot be loaded into the shelter, nor can it be supported by the shelter.
3. The entire device must fit within a circle with a 30.0-cm radius.
4. Only flat (not rounded) toothpicks may be used (e.g., Diamond, Chenille Kraft, or comparable brand in terms of mass, length & width). Toothpicks may be broken but must be recognizable.
5. Only water-based white school glue may be used. Glue can only connect toothpicks, not protect the egg (e.g., no glue webs permitted).

Testing Procedure:

1. At the competition, fresh grade-A large chicken eggs will be made available by the organizers. Your team can choose between at least ten eggs, which may not be altered any way.
2. The egg will be placed into a plastic sandwich bag, to aid in clean up, at the center of a target circle marked on the floor.
3. An appointed member of your team places your bomb shelter on top of the egg and notifies the judges that testing can begin.
4. A judge will drop a regulation Major League baseball through a tube with its lower end 0.5-meters above the center of a 30-cm target circle marked on the floor.
5. The first trial will be made with the baseball dropped from a height of 1.5-meters above the floor. After the drop, when instructed by a judge, the team member that placed the shelter over the egg will remove the shelter and allow the judge to inspect the egg. If, upon inspection by the judges, there is liquid leaking from the egg, the team may appoint a second team member for a repeat trial at a drop height of 1.5-meters, with the same rules and a new shelter. This can be repeated with the next member of the team until all four shelters are used.
6. If there is no liquid leaking from the egg, the team is eligible for a new trial from a height of 2.0-m, rotating through team members and otherwise following the same rules as the first. A trial from 2.5-m, is available if the team has remaining shelters after success at 2.0-m. A final trial, from 3.0-m, is available if the team has a final shelter remaining after success at 2.5-m.

Scoring:

Shelter must protect the egg AND keep the baseball inside the target circle – i.e. the device “catches” the ball rather than deflects it. In order to count as being in the target circle, no part of the baseball may be touching the line or go over the line at any point. The line is “out.”

Rankings are determined by the largest sum of each team’s four shelter scores, based on the formula:

Score=[(Impact)(Bonus)] / [(Height)(Mass)]

• Height of the shelter’s tallest point above the floor, measured in centimeters to the nearest mm.

• Mass of the shelter, measured in kilograms to the nearest 0.01 gram.

• Impact is a multiplicative factor based on height:

  • • 1.0 for 1.5-m trials, 1.5 for 2.0-m trials, 3.0 for 2.5-m trials, 10 for 3.0-m trial

• Bonus is a multiplicative factor based on the following conditions:

  • 3 for shelters that protect egg from leaking AND keep ball within the target circle

  • 1 for shelters that protect egg from leaking BUT do not keep ball within circle

  • 0 disqualified when egg is cracked enough to leak so that daubing with tissue indicates liquid

 

Plan-Ahead Event: Bomb Disposal Manipulator Arm

Goal:

Using only plastic soda straws and metal straight pins, design and construct the longest possible arm which will support a 50-gram mass.

Materials:

The competition organizers will provide each team with:

• 15 jumbo plastic 73⁄4” or 10” soda straws

• 12 metal sewing #17 straight pins

• 1 metal #1 paper clip

• 50-gram mass, attached to a 30-cm long loop of string.

• 1 identifying label

• 1 small safety scissors (the kind they let you use in elementary school)

Wire cutting pliers will provided at the “pin cutting station”

Students must bring their own:

• safety goggles (required in the “pin cutting station”) and recommended, but not required, gloves

Design Procedure:

• Prior to the day of the competition, teams should obtain their own straws and pins to allow development of a manipulator arm that will successfully meet the goals

• On the day of the competition, during on-site registration, each team is required to submit to the judges a single 8.5x11 inch sheet of paper with sketches of construction plans for their manipulator arm.

• The event organizers will initial the plans, note their submission on the event score sheet, and return the plans for use by the team during the construction phase.

• Teams are forbidden from bringing any physical model of their manipulator arm to the competition.

Construction Procedure:

1. All assembly must be done at the competition during the 20-minute construction period with the provided straws and pins.

2. Scissors are the only tools allowed at the team tables.

3. If students wish to cut pins, they must move to the “pin cutting station” to complete this process. Goggles and protective gloves will NOT be provided. Students will not be allowed to cut pins without wearing goggles and gloves. If no goggles are worn, then the pins cannot be cut. If pins are cut without the use of goggles, that team will be disqualified for this event.

4. If pins bend or break during construction, they will not be replaced.

5. Teams may perform their own tests of their devices during the construction phase.

6. The mass must be hung by the paperclip (i.e., it cannot be tied by the string directly to the arm). The paper clip, bent to an “S” shape, is to be used only for attaching the 50-gram mass to the manipulator arm by hooking it to a single straw or pin. The paper clip may not be used to strengthen or help construct the arm in any manner.

7. At the end of the 20-minutes all construction must immediately cease. Each team shall affix the label to its manipulator arm and their 50-gram mass, and immediately deliver them to the judge’s table. After delivering the arm and mass, the team members may not touch any of the manipulator arms at the judge’s table until that team is called for the test phase and asked to bring its device to the testing table.

8. At the conclusion of the construction period, each team will complete a testing sheet by designating which team member will serve in the four roles for the final phase of the competition:

   1. Coordinator: This person, when the team is called for testing, will deliver the manipulator arm from the judge’s table to the testing table, and will be responsible for making sure the other team members follow all event rules and meet the designated time restrictions.

   2. Holder: This team member is responsible for holding the straw manipulator arm in contact with, not secured to, the tabletop and positioning it with respect to the edge of the testing table.

   3. Hanger: This team member will use the #1 paper clip bent into an “S” shape to attach to their manipulator arm the 50-gram mass hanging from a 30-cm string.

   4. Timer: This team member will use the provided stopwatch to measure the time periods established for the testing procedure.

Testing Procedure:

There will be two testing trials for the device, each a 15-second long period during which the manipulator arm is supported by the Holder while the mass is suspended from the far end.

1. When called to compete, the team member appointed as Coordinator will pick up their device from the judge’s table, and carry it to the testing table. Absolutely no modifications are allowed after the end of the 20-minute construction period. This prohibition includes replacing straws or pins which have pulled loose from the arm.

2. The Holder receives the device from the Coordinator and positions it in the desired the edge of the testing table. No part of the Holder's body may extend beyond the test edge of the table, any violation of this restriction forfeits test with the ability for a do-over.

3. Once the manipulator arm is in the selected position, the Hanger will attach the mass by placing the loop of the string attached to the 50-gram mass over the hook end of the paper clip. The Holder may not touch any part of the apparatus that extends beyond the table once the Hanger approaches the device, violation of this restriction forfeits test with the ability for a do-over.

4. As soon as the team member hooks the string so tension is supplied by the 50-gram mass, the Hanger steps completely away from the arm. The Timer then announces to the judge that s/he is beginning to measure the 15-second testing period.

5. If the design of the manipulator arm is such that the end with the mass is higher than the tabletop, the 30- cm loop of string must extend below the top of the table so the judge can accurately measure the overhang distance at table-top height.

6. The manipulator arm must support the mass above the floor for 10 seconds without any straws "crimping" (developing a fold line across the straw) due to the load.

7. dAt the end of the 15-second testing period, the judge immediately establishes whether the device survived without crimping and promptly measures the overhang distance along a horizontal line perpendicular to the table edge from the point directly above the point of attachment of the weight. As soon as the measurement is made, the Hanger can remove the mass.

8. If the device survives the first testing trial, the team has 60-seconds to reset the manipulator arm in preparation for a second testing trial with the same rules.

Scoring:

At the conclusion of each testing period, a judge will measure and record the overhang distance. Within each scoring tier, this distance will determine the ranking. There will be four tiers for the scoring:

1. devices that survive both of the 10-second testing trials will be ranked according to the maximum overhang distance, with the longest recorded distance ranked highest;

2. devices the survive the first, but not the second trial, will be ranked after the first tier;

3. devices that do not survive the initial trail will be ranked after the second tier; and

4. devices without a submitted design will be ranked in the lowest tier, according to their testing survival.

 

Communication/Calculation Challenge:

Details of the Communication/Calculation challenge will be posted here soon. Please check back for updates.

 

Impromptu Team Activity

Activity is the key word for this competition, with the goal being for each team to achieve the desired results as quickly as possible. The instructions regarding this event are not released until it begins, so everyone is on equal footing. The situation is designed to reward teamwork and common sense thinking as well as knowledge of physics. Every team will come away with smiles and good memories regardless of how well they master the particular challenge.

 

Order-of-Magnitude Quiz (also known as Fermi Questions)

Arrive at a reasonable approximation for the value of a complex situation with very little to no information available to directly compute the answer. In this quiz, the contestants will need to quickly make assumptions for values to use in simple calculations in order to arrive at the "correct" answer, stated as the power of ten of the number that fits the accepted value.

Teams will receive 9 questions to complete within 15 minutes. The teams can divide the work in any way they see fit, but only one answer per question per team will be accepted. Answers will be judged according to how many orders of magnitude the team's answer is from the judge's solution. The lowest score wins -- 0 points awarded for the answer accepted by the panel of judges, with 1 point scored per order of magnitude from the accepted value.

Examples of Order-of-Magnitude Quiz questions include:

• How many electrons enter the starter motor when a new, full-sized pickup starts?
• How many times would a tire of a Ford Taurus rotate when driven from NYC to LA?
• Estimate the number of gallons of gasoline used annually by all the cars in the USA.