Download CTS Heat and Temperature LeaPs 2010

CTS Heat and Temperature
LeaPs 2010
Adult Content Knowledge:
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Heat moves in three ways: conduction, convection and radiation
Heat, energy flows spontaneously from hot to cold
Most everything that goes on in universe is a transformation of energy for example an exploding
star
Many types of energy
Heat is the total amount of energy in a materials (Kinetic Energy + Potential Energy)
Temperature is scale that measures the amount of heat – added or removed
Different temperature scales – F, C and K (absolute zero)
Energy can shift one form to another, but total amount is constant
Energy tends to “leak out” as heat
Dispersal of Energy –accumulated waste energy from system ends up as heat released to
environment
Systems go from order to disorder unless energy is added
Instructional Implications:
When designing instruction it’s as important to consider HOW to teach as WHAT to teach.
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Things give off heat
K-2 it is all about the sun
Don’t confuse heat with cold
Warm objects warms a cooker object
Touching, at distance (heat transfer)
1 place that provides definition of word up front -> Energy
Don’t have to distinguish heat from T by 5th grade
Boiling Point, Melting Point, solubility
Types of Energy
Heat transfer
Problematic because can’t see
There is almost always heat loss in any transfer
Amount heat
Must be able to measure
The Kelvin scale, but not calculating it
Concepts
K2
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Sun warms land and water
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Heat moves warmer to cooker
Sun’s Energy
Conductors and insulators
Heat produced in many ways
Optics
Warm stuff heats cook stuff
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Energy not created or destroyed
Heat transferred by movement of atoms through materials or across space by radiation
Sun’s energy produces change on earth
Heat energy always a product of energy transformation generally not useful
Different forms of energy (A. C. Helms: acronym for recalling the different forms of energy)
Lt interacts with matter
Energy interacts with matter
Heat moves in predictable ways
3-5
MS
Misconceptions
 Even after yrs of instruction, students do not distinguish well between heat and temperature when
they are explaining thermal phenomena.
 The belief that temp is the measure of heat is very resistant to change.
 Middle school students do not always explain the process of heating and cooling in terms of heat
being transferred.
 Think cold is transferred from cold objects to warm objects or both heat and cold are transferred at
the same time.
 Do not always explain heat-exchange phenomena as interactions.
 Believe some substances can’t heat up: flour, sugar, air, etc)
 Metals get hot quickly because they “attract heat”, “suck heat in” or “hold heat well”
 Middle School: different materials have different temps if they feel different---therefore they do
not recognize the universal tendency to temperature equalization.
 Few understand molecular basis of heat transfer even after instruction.
 Tend to think of heat as a substance largely in part to language and cultural influences.
 Tend to think heat has fluid characteristics.
 Hot and cold are not part of the same continuum. Cold is the opposite of heat.
 Know heat rises, hot things expand, heat travels through metals..but CAN NOT explain why.
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Think that temperature is a property of a material.
Heat is hot, but temperature can be cold or hot (common with 10-12 year olds)
No difference between heat and temperature: “Temperature is heat” (10-16 yr olds)
Less than 25% of 13-14 yr olds correctly predicted an average temperature when differing temps of
materials (water) are mixed when given beginning temps of all the liquid.
Amount of material effects the temperature.
Conductors and insulators are opposites with insulators having no degree of conducting ability.