Build and Test Heat Device - Middle School Physical Science
Card 1 of 25
If $T_i = 80,^{\circ}\text{C}$ and $T_f = 65,^{\circ}\text{C}$, what is $\Delta T$ using $\Delta T = T_f - T_i$?
If $T_i = 80,^{\circ}\text{C}$ and $T_f = 65,^{\circ}\text{C}$, what is $\Delta T$ using $\Delta T = T_f - T_i$?
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$-15,^{\circ}\text{C}$. Substituting: $65 - 80 = -15$ (temperature decreased).
$-15,^{\circ}\text{C}$. Substituting: $65 - 80 = -15$ (temperature decreased).
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Choose the better design to increase heat loss: add a metal fin or add a foam sleeve to a hot container.
Choose the better design to increase heat loss: add a metal fin or add a foam sleeve to a hot container.
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Add a metal fin. Metal fins conduct heat away rapidly to surrounding air.
Add a metal fin. Metal fins conduct heat away rapidly to surrounding air.
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Choose the better design to reduce heat loss: thick foam wrap or thin aluminum wrap on a cup.
Choose the better design to reduce heat loss: thick foam wrap or thin aluminum wrap on a cup.
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Thick foam wrap. Foam's trapped air provides better insulation than thin metal.
Thick foam wrap. Foam's trapped air provides better insulation than thin metal.
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Identify the dominant heat transfer method across a vacuum gap: conduction, convection, or radiation.
Identify the dominant heat transfer method across a vacuum gap: conduction, convection, or radiation.
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Radiation. Only electromagnetic waves can cross empty space.
Radiation. Only electromagnetic waves can cross empty space.
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What formula gives temperature change from initial and final temperature measurements?
What formula gives temperature change from initial and final temperature measurements?
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$\Delta T = T_f - T_i$. Subtracting initial from final gives the change in temperature.
$\Delta T = T_f - T_i$. Subtracting initial from final gives the change in temperature.
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Which option increases heat transfer fastest from a hot object: metal contact or plastic contact?
Which option increases heat transfer fastest from a hot object: metal contact or plastic contact?
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Metal contact. Metals conduct heat much better than plastics due to free electrons.
Metal contact. Metals conduct heat much better than plastics due to free electrons.
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Which option best reduces convection from a hot liquid: an open top or a tight lid?
Which option best reduces convection from a hot liquid: an open top or a tight lid?
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A tight lid. Lids block rising hot air from escaping the container.
A tight lid. Lids block rising hot air from escaping the container.
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Identify the independent variable in a test comparing felt wrap versus foil wrap on a container.
Identify the independent variable in a test comparing felt wrap versus foil wrap on a container.
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The insulating material (felt versus foil). The material type is what you deliberately change to test.
The insulating material (felt versus foil). The material type is what you deliberately change to test.
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Which design feature most increases conduction between a hot object and the air: more contact area or less contact area?
Which design feature most increases conduction between a hot object and the air: more contact area or less contact area?
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More contact area. Larger surface area allows more particle collisions for heat transfer.
More contact area. Larger surface area allows more particle collisions for heat transfer.
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Which surface increases radiative heat transfer best: shiny silver or matte black?
Which surface increases radiative heat transfer best: shiny silver or matte black?
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Matte black. Dark surfaces absorb and emit infrared radiation efficiently.
Matte black. Dark surfaces absorb and emit infrared radiation efficiently.
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Which surface reduces radiative heat transfer best: shiny silver or matte black?
Which surface reduces radiative heat transfer best: shiny silver or matte black?
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Shiny silver. Reflective surfaces bounce infrared radiation away.
Shiny silver. Reflective surfaces bounce infrared radiation away.
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What is the main reason trapped air in foam reduces heat transfer?
What is the main reason trapped air in foam reduces heat transfer?
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Air is a poor conductor and limits convection. Still air prevents heat movement by both conduction and convection.
Air is a poor conductor and limits convection. Still air prevents heat movement by both conduction and convection.
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Which option best describes a conductor: low or high thermal conductivity?
Which option best describes a conductor: low or high thermal conductivity?
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High thermal conductivity. Conductors allow easy heat flow through mobile electrons.
High thermal conductivity. Conductors allow easy heat flow through mobile electrons.
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Which option best describes an insulator: low or high thermal conductivity?
Which option best describes an insulator: low or high thermal conductivity?
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Low thermal conductivity. Insulators resist heat flow due to poor particle energy transfer.
Low thermal conductivity. Insulators resist heat flow due to poor particle energy transfer.
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What is thermal energy transfer by radiation?
What is thermal energy transfer by radiation?
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Transfer by electromagnetic waves, no medium required. Heat travels as infrared waves through empty space.
Transfer by electromagnetic waves, no medium required. Heat travels as infrared waves through empty space.
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What is thermal energy transfer by convection?
What is thermal energy transfer by convection?
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Transfer by moving fluids due to density differences. Hot fluids rise and cold fluids sink, creating circulation.
Transfer by moving fluids due to density differences. Hot fluids rise and cold fluids sink, creating circulation.
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What is thermal energy transfer by conduction?
What is thermal energy transfer by conduction?
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Transfer by direct contact between particles. Heat flows when particles collide and transfer kinetic energy.
Transfer by direct contact between particles. Heat flows when particles collide and transfer kinetic energy.
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What is the best controlled variable when comparing two insulating designs for a cup?
What is the best controlled variable when comparing two insulating designs for a cup?
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Same cup, same liquid volume, same starting temperature. Controlling variables ensures only the insulation differs between tests.
Same cup, same liquid volume, same starting temperature. Controlling variables ensures only the insulation differs between tests.
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Identify the dependent variable in a test of insulation where temperature is recorded over time.
Identify the dependent variable in a test of insulation where temperature is recorded over time.
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The temperature (or temperature change) of the contents. Temperature changes based on the insulation effectiveness.
The temperature (or temperature change) of the contents. Temperature changes based on the insulation effectiveness.
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Find the correct comparison: for the same conditions, which cools faster, a metal cup or a foam cup?
Find the correct comparison: for the same conditions, which cools faster, a metal cup or a foam cup?
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Metal cup. Metal's high conductivity transfers heat out much faster than insulating foam.
Metal cup. Metal's high conductivity transfers heat out much faster than insulating foam.
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Which design increases heat transfer to warm an object faster: larger surface area or smaller surface area?
Which design increases heat transfer to warm an object faster: larger surface area or smaller surface area?
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Larger surface area. More area allows more heat to flow per unit time at same temperature difference.
Larger surface area. More area allows more heat to flow per unit time at same temperature difference.
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Identify the best design choice to reduce radiation: shiny outer surface or black outer surface?
Identify the best design choice to reduce radiation: shiny outer surface or black outer surface?
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Shiny outer surface. Reflects thermal radiation back instead of absorbing and re-emitting it.
Shiny outer surface. Reflects thermal radiation back instead of absorbing and re-emitting it.
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Identify the best design choice to reduce convection in a container: sealed lid or open top?
Identify the best design choice to reduce convection in a container: sealed lid or open top?
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Sealed lid. Prevents air movement that would carry heat away by convection.
Sealed lid. Prevents air movement that would carry heat away by convection.
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Identify the best design choice to reduce conduction: thick metal wall or thick foam wall?
Identify the best design choice to reduce conduction: thick metal wall or thick foam wall?
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Thick foam wall. Foam has low thermal conductivity while metal conducts heat rapidly.
Thick foam wall. Foam has low thermal conductivity while metal conducts heat rapidly.
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Which tool is most appropriate to measure temperature change during device testing?
Which tool is most appropriate to measure temperature change during device testing?
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Thermometer or temperature probe. Directly measures the quantity that indicates heat transfer effectiveness.
Thermometer or temperature probe. Directly measures the quantity that indicates heat transfer effectiveness.
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