Download - Keep the Heat a recycled event
Keep the Heata recycled event
October 2011
The object is to construct a device that is able to retain heat. Students will also be tested on thermodynamic
concepts.
Students must wear appropriate eye protection.
Devices will be impounded.
ParametersStudents MUST bring:
-their own insulating device-2 identical 250 ml Pyrex beakers-eye protection-Plots (known by normal people as graphs)-Writing utensils
They also MAY bring-notes (must be 3-hole punched in a binder)-parts and supplies-calculator
Supplied by Supervisor
-hot water-Devices for transferring measured volumes of water to team beakers.-thermometers or probes
Plots (Graphs!!??)Prior to competition students must test their device.Data collected must be displayed on up to 4 graphs (may be all in 1)Data should show the relationship between elapsed cooling time and ending water temperature.Variables should include amount of water and starting water temperature
More on PlotsMay be computer generated or handwritten.Must be properly labeled.May be required to submit prior to competitionMust have a duplicate set to use during competition.Students may be asked about their data and how they use their plots.
Impounding
Teams must impound-their device-parts and supplies (beakers; tools;
notes; plots)-appeals will not be processed after the
device is removed from competition.-all parts of the device must be
approximately room temperature at impound.
Eye Protection
Must be worn during set-up and loading of their device.
If time allows they may be given the chance to obtain eye protection. If this is not possible they may not compete in Part 1
Construction Materials
Only allowable materials-wood; paper; cardboard; natural fibers; organic granular material; aluminum foil
Fastening materials may be:-tape; glue; screws; bolts; nuts; nails; string
Fastening materials are only to be used for securing the components together.
Prohibited Materials
-foam (plastic; metal; expandable glue-plastic-bubble wrap-glass-commercial insulation
The Device
Must allow for the easy insertion and removal of a 250 ml beaker.Must accommodate the insertion and removal of a thermometer via a hole 1.5 cm in diameter directly above the beaker and will remain open during the competition. The top of the hole should be less than 5 cm above the lip of the beaker.
Inspection
Devices will be inspected to look for energy sources such as electrical components; battery powered heaters; chemical reactions.At the end teams must disassemble their devices to verify compliance with all rules.
The Competition
After Impound:-the temperature of the source water
will be announced-the volume of the water to be used
will be given -the cooling time will be announced-the ambient room temperature will
be announced.
Competition Teams will have 5 minutes to set up their devices at the start of competition.Water will be given to teams in a staggered sequence. Both beakers will be filled with the same amount of water. (one inside device and the other next to it.)Supervisors will record the time that the team received their water.
StudentsMust use their graphs to calculate the temperature of the waterThey must supply the supervisor with their estimate at the end of the cooling time prior to the supervisor measuring the actual temperature.
The Cooling TimeAt the end of the cooling period the supervisor will record the temperature in each beaker. Thermometers may be left in for the full time or may be reused for each station after necessary measures are taken to make sure all devices receive the exact same treatment. This will be announced prior to impound
Written Test (50 pts)-Each team will be given the same amount of time to compete after all devices have been loaded.-Topics include temperature conversions; definition of heat units; thermal conductivity; heat capacity; specific heat; the laws of thermodynamics; the history of thermodynamics and thermodynamic processes
Scoring
High score winsAll calculations are to be done in Celsius.Ranking will be done in two tiers
-the highest are those with no violations of rules
- the other group includes teams with any violation.
Scoring of Graphs
10 points total-2 for proper labeling-2 for appropriate title of graph and axes-2 for appropriate units and axis labels-1 for each data plot on a graph (up to 4)
Final Score
Sum of four componentsTest score - 50 pointsGraph score - 10 pointsHeat Score - up to 50 pointsPrediction Score - up to 25 points
Score
Heat Retention ScoreInternal Beaker temperatureExternal Beaker temperature
1( ) X 50
55.8°38°
1 )( x 50 = (1.55 - 1) x 50 = 22.5
Score
Prediction Score Final Int temp - Predicted Int temp Final Int. temperature( ) X 25
55.8° - 49°1 )( x 25 = (1- 0.12) x 25 = 22
1
55.8°
Final Score
Add all components together
Test Score (50) 40Graph Score (10) 10Heat Retention Score (50) 22.5Prediction Score (25) 22
Totalout of possibe 135
90.5
Written Test
Worth 50 Points
Entirely on thermodynamics - not scary - just a big word for heat.
Don’t let your students be beaten by vocabulary. Have them build a binder with everything they should know - especially vocabulary.
Written Test
Temperature Conversions - use a chart for heaven’s sake.
Heat Units calorie jouleThermal conductivityHeat CapacitySpecific HeatLaws of ThermodynamicsHistory of ThermodynamicsThermodynamic Processes
Simply Put
• States of Matter• Changes in State• Heat transfer• Specific Heat• Q = mC∆t• Thermometer scales• Heat vs temperature• Calorimeter• Units
More• The First law of Thermodynamic is merely
the law of Conservation of energy• The Second states the heat cannot be
transferred from a colder to a hotter body and that the entropy of an energy system increases with time. (chaos) Perfect order in the Universe occurred the second after the Big Bang when matter; energy and forces were most organized.
And
• The Third law states that if all the thermal motion of an energy system could be removed that a state called absolute zero could be attained.
• http://www.physicalgeography.net/fundamentals/6e.html
A Brief History of thermodynamics
• www.sussex.ac.uk/chemistry/.../a_thermodynamics_history.pdf
• Joule• Gas laws• Kinetic Theory• Heat Transfer• Laws of Thermodynamics• Wikipedia History of thermodynamics
Thermodynamic Processes
• www.allianceforwaterefficiency.org/.../EBMUD_WaterSmart_Guide_...
• Cooling towers• Boilers and heating elements
– Steam vs hot water
Resources
• http://www.engineeringtoolbox.com/heat-work-energy-d_292.html
• The Physics Classroom• Phun Physics! U of Virginia• http://physics.about.com/od/
thermodynamics/p/thermodynamics.htm