Which Cup Keeps Ice Cold the Longest? Insulation Test
Heat moves from warm to cool — the warm room's heat sneaks into the cold
Learning Objective
Students will learn that heat moves from warmer things into cooler things — and that **insulation** slows that heat down — by running a fair test: identical ice cubes in a metal cup, a paper cup, and a foam cup, measuring which melts last. (TEKS 3.6D — materials as engineering choices; TEKS 3.8A thermal energy; NGSS 3-5-ETS1-3 fair tests.)
What You'll Learn
- Insulation is a material that slows heat down — foam and trapped air are
- Metal feels cold to touch AND melts ice fastest — it carries heat quickly in
- A fair test: same ice cubes, same room, same start time — only the cup
- The cup doesn't "make cold" — it just slows the heat trying to get in.
Words to Know
- Insulation
- Material that slows heat down — keeps cold in, heat out.
- The foam cup's insulation kept the ice frozen longest.
- Conductor
- Material that lets heat zoom through fast.
- The metal cup conducted heat right to the ice.
- Fair test
- Changing only one thing so the result means something.
- Same ice, same room — only the cups changed.
- Heat
- Energy that moves from warm things into cooler things.
- The room's heat sneaked into the ice cubes.
- Trapped air
- Tiny air pockets inside material that slow heat down.
- The foam's trapped air bounced the heat away.
Check What You Learned
Quick Quiz
1 / 5Which way does heat move?
Fun Facts
Heat moves from warmer objects to cooler objects — the warm room's heat flows into the cold ice cube and melts it
Source: TEKS 3.8A — thermal energy moves; standard heat-transfer direction
Insulation is material that slows heat transfer — foam and trapped air pockets are effective insulators because air is a poor conductor
Source: standard insulation/elementary material properties
Metal is a thermal conductor — heat passes through it quickly, so ice in a metal cup melts fastest
Source: standard conductor/insulator property tables
A Thermos/vacuum flask traps a vacuum layer between walls — almost no particles to carry heat — keeping drinks hot or cold for hours
Source: vacuum-flask design, standard physics
A fair test changes only one variable — here, cup material — while keeping ice size, room, and start time identical
Source: NGSS 3-5-ETS1-3 controlled tests
The cup doesn't create cold — it only slows the heat trying to get in; all cubes eventually melt
Source: heat always flows warm→cool until equal
Lesson Info
Standards Alignment
- TEKS 3.6D
demonstrate that materials can be combined/selected based on physical properties to create solutions (insulation as a material choice)
- TEKS 3.8A
identify examples of thermal energy (heat moving warm→cool)
- 3-5-ETS1-3
plan and carry out fair tests in which variables are controlled
Keywords
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