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ThermodynamicsIntroStarter track

Concept module

Heat Transfer

See heat as energy transfer driven by temperature difference while conduction, convection, and radiation compete on one compact bench with honest pathway rates.

Interactive lab

Keep the stage, graph, and immediate control feedback in one working view.

Time

0.00 s / 60.0 sLivePause to inspect a specific moment, then step or scrub through it.

0.00 s60.0 s

Heat Transfer

One compact heat-flow bench keeps conduction, convection, radiation, and the shared temperature gap on the same honest state instead of splitting them into separate toy demos.

Graphs

Switch graph views without breaking the live stage and time link.

Block and room temperatures

Track the hot block against the fixed room temperature. As the gap shrinks, the pathway rates below must shrink too.

time (s): 0 to 60temperature (degC): 0 to 256

Hot blockRoom and bench

Hover or scrub to link the graph back to the stage.time (s) / temperature (degC)

Controls

Adjust the physical parameters and watch the motion respond.

Hot-block temperature

T_{hot}

145 degC

Sets the block's starting temperature before the run begins.

Room temperature

T_{room}

25 degC

Raises or lowers the surrounding bench and air temperature.

Material conductivity

k_{mat}

1.5

Changes how effective the solid-conduction path is.

Contact quality

χ

0.8

Changes how well the block actually touches the bench.

More tools

Secondary controls, alternate presets, and less-used toggles stay nearby without crowding the main bench.

Hide

Surface area

A

1.1

Scales the shared and exposed area used by the transfer paths on this bench.

Airflow

h_{air}

Makes the surrounding air more still or more actively moving.

More presets

Presets

Predict -> manipulate -> observe

Keep the active prompt next to the controls so each change has an immediate visible consequence.

ComparePrompt 1 of 5

Compare mode is most useful here when Setup A and Setup B keep nearly the same temperature contrast but different contact or area. Then the total-rate difference comes from the transfer path, not from a hidden delta-T change.

Try this

Clone Metal on cool bench into compare mode, weaken only Setup B's contact quality, and watch the two total-rate badges separate while the delta-T badges stay similar.

Equation map

See each variable before you move it.

Select a symbol to highlight the matching control and the graph or overlay it most directly changes.

T_{hot}

Hot-block temperature

145 degC

Sets the starting temperature of the block, which controls the initial contrast with the room.

Graph: Block and room temperaturesGraph: Rate vs temperature contrastOverlay: Temperature-gap bridge

Equations in play

Choose an equation to sync the active symbol, control highlight, and related graph mapping.

More tools

Detailed noticing prompts, guided overlays, and challenge tasks stay available without taking over the main bench.

Hide

What to notice

Use one prompt at a time. Each one keeps the heat-transfer story tied to one temperature gap and one honest pathway split.

ComparePrompt 1 of 5

Try this

Clone Metal on cool bench into compare mode, weaken only Setup B's contact quality, and watch the two total-rate badges separate while the delta-T badges stay similar.

Why it matters

It separates transfer-rate causes now, before later concepts ask how that transferred energy changes temperature or supports phase change.

Control: Contact qualityControl: Surface areaControl: Hot-block temperatureControl: Room temperatureGraph: Contact responseGraph: Pathway rates over timeOverlay: Temperature-gap bridgeOverlay: Pathway splitEquation

χ

Equation

A

Equation

T_{hot}

Equation

T_{room}

Guided overlays

Focus one overlay at a time to see what it represents and what to notice in the live motion.

4 visible

Overlay focus

Temperature-gap bridge

Shows the shared temperature difference and the net flow direction from hotter toward cooler.

What to notice

When the two temperature chips move closer together, every transfer pathway shrinks because the common driving difference is smaller.

Why it matters

It keeps heat tied to a temperature difference instead of turning heat into a stored substance.

Control: Hot-block temperatureControl: Room temperatureGraph: Block and room temperaturesGraph: Rate vs temperature contrastEquation

T_{hot}

Equation

T_{room}

Challenge mode

Use the same heat-flow bench for compare and tuning challenges. The checks read the live rates and temperature contrast, so the success state stays tied to one honest simulation state.

0/2 solved

MatchStretch

1 of 7 checks

Same contrast, slower loss

Start from Metal on cool bench, switch to compare mode, and edit only Setup B until it keeps nearly the same temperature contrast as Setup A but loses energy at less than half the rate.

Compare modeGraph-linkedGuided start2 hints

Suggested start

Leave Setup A as the strong-contact baseline and edit only Setup B.

Pending

Open the Contact response graph.

Block and room temperatures

Matched

Keep the Pathway split visible.

Pending

Stay in compare mode while editing Setup B.

Explore

Pending

Keep Setup A temperature contrast between 123 degC and 127 degC.

Pending

Keep Setup B temperature contrast between 123 degC and 127 degC.

Pending

Keep Setup B contact quality between 0.15 and 0.3.

Pending

Keep Setup B total rate between 18 u/s and 30 u/s.

The checklist updates from the live simulation state, active graph, overlays, inspect time, and compare setup.

At t = 0 s, the block is at 145 degC while the room is 25 degC, so the temperature contrast is 120 degC. The pathway rates are 28.51 u/s by conduction, 11.88 u/s by convection, and 5.73 u/s by radiation, for a total of 46.12 u/s. Energy is leaving the hotter block because it is above room temperature. Conduction is strongest here because the material-contact path is doing most of the transfer.

Equation detailsDeeper interpretation, notes, and worked variable context.

Total transfer rate

The net heat-transfer rate is the sum of the three visible pathways on this bench.

\overset{q}{˙}_{total} = \overset{q}{˙}_{cond} + \overset{q}{˙}_{conv} + \overset{q}{˙}_{rad}

k_{mat}

Material conductivity 1.5

χ

Contact quality 0.8

A

Surface area 1.1

h_{air}

Airflow strength 1

Conduction scaling

Conduction gets stronger when the material path conducts better, the contact is better, the shared area is larger, or the temperature contrast is larger.

\overset{q}{˙}_{cond} \propto k_{mat} χ A (T_{hot} - T_{room})

The contact factor chi is a bounded stand-in for how well the two surfaces actually touch.

T_{hot}

Hot-block temperature 145 degC

T_{room}

Room temperature 25 degC

k_{mat}

Material conductivity 1.5

χ

Contact quality 0.8

A

Surface area 1.1

Convection scaling

Convection rises with exposed area, temperature contrast, and how strongly the surrounding air is moving.

\overset{q}{˙}_{conv} \propto h_{air} A (T_{hot} - T_{room})

T_{hot}

Hot-block temperature 145 degC

T_{room}

Room temperature 25 degC

A

Surface area 1.1

h_{air}

Airflow strength 1

Radiation scaling

Radiation needs no contact and grows especially quickly when the temperature contrast is large.

\overset{q}{˙}_{rad} \propto ε A (T_{hot}^{4} - T_{room}^{4})

The fourth-power dependence is why the radiation curve bends upward on the contrast graph.

T_{hot}

Hot-block temperature 145 degC

T_{room}

Room temperature 25 degC

A

Surface area 1.1

Cooling response

The block cools faster when the total outward transfer rate is larger and more slowly as the temperature gap collapses.

\frac{d T _{hot}}{d t} = - \frac{q ˙ _{total}}{C _{block}}

T_{hot}

Hot-block temperature 145 degC

T_{room}

Room temperature 25 degC

Progress

Not startedMastery: NewLocal-first

Start exploring and Open Model Lab will keep this concept's progress on this browser first. Challenge mode has 2 compact tasks ready. No finished quick test, solved challenge, or completion mark is saved yet.

Let the live model runChange one real controlOpen What to notice

Try this setup

Copy the live bench state and reopen this concept with the same controls, graph, overlays, and compare context.

Stable links

Starter track

Step 3 of 40 / 4 complete

Thermodynamics and Kinetic Theory

Earlier steps still set up Heat Transfer.

1. Temperature and Internal Energy2. Ideal Gas Law and Kinetic Theory3. Heat Transfer4. Specific Heat and Phase Change

Previous step: Ideal Gas Law and Kinetic Theory.

Start from track beginning

Short explanation

What the system is doing

Heat is not something a block stores by itself. On this bench, heat means energy crossing a boundary because one side is hotter than the other, so the direction and rate always come back to the temperature difference.

The same hot block can lose energy three beginner-friendly ways at once. Conduction uses the material-contact path into the bench, convection uses moving air that carries energy away, and radiation uses thermal emission that still works even with no solid contact.

This page stays bounded on purpose. It gives you one honest rate picture before later specific-heat or phase-change questions ask what that transferred energy does to temperature once it arrives.

Key ideas

01Heat is energy transfer due to temperature difference, not a substance the hot object contains.

02Conduction gets stronger when the material path is more conductive, the contact is better, or the shared area is larger.

03Convection depends on moving fluid and exposed area, so stronger airflow can speed the transfer without changing the solid-contact path.

04Radiation needs no contact and grows more quickly at large temperature contrast, which is why very hot objects can radiate strongly even in still air.

Live worked example

Solve the exact state on screen.

Use the current setup directly. The same block, room, and pathway rates drive both worked examples, so the formulas stay tied to one visible heat-flow state.

Live valuesFollowing current parameters

For the current setup, what is the temperature contrast and how is the total transfer rate split across conduction, convection, and radiation right now?

T_{hot}

Hot-block temperature

145 degC

T_{room}

Room temperature

25 degC

Δ T

Temperature contrast

120 degC

\overset{q}{˙}_{total}

Total transfer rate

46.12 u/s

1. Read the driving difference

The block is at

T_{hot} = 145 degC

while the room is

T_{room} = 25 degC

, so the current contrast is

Δ T = 120 degC

2. Read each pathway rate

Right now the live rates are

\overset{q}{˙}_{cond} = 28.51 u/s

\overset{q}{˙}_{conv} = 11.88 u/s

, and

\overset{q}{˙}_{rad} = 5.73 u/s

3. Rebuild the total from the parts

Adding the three visible pathways gives a total transfer rate of

\overset{q}{˙}_{total} = 46.12 u/s

Live pathway split

\overset{q}{˙}_{cond} = 28.51 u/s, \overset{q}{˙}_{conv} = 11.88 u/s, \overset{q}{˙}_{rad} = 5.73 u/s

Conduction is dominant here because the material-contact path is strong while the room stays cooler than the block.

Common misconception

If an object is hot, it simply contains a lot of heat.

A hot object contains internal energy, but heat refers to the energy crossing into or out of the object because of a temperature difference.

That is why the same object can gain heat, lose heat, or have almost no net heat transfer depending on what surrounds it.

Mini challenge

Two identical hot blocks start at the same temperature in the same room. Block A sits flat on a metal bench with good contact. Block B barely touches an insulating pad. Which block loses energy faster at first, and why?

Prediction prompt

Decide which pathway changes even before either block has time to cool much.

Check your reasoning

Block A loses energy faster at first because the stronger material-contact path makes conduction much larger.

At the same initial temperature contrast, the big difference is the contact path. Better material conductivity and better contact quality raise the conduction rate immediately, so the total heat-transfer rate is larger even before the temperatures have had much time to change.

Quick test

Reasoning

Question 1 of 5

Answer from the live bench, not from slogans. The goal is to keep direction, pathway, and rate reasoning connected to the same temperature gap.

On this page, what does heat mean most directly?

Choose one answer to reveal feedback, then test the idea in the live system if a guided example is available.

Accessible description

The simulation shows a hot block on the left and a cooler room-and-bench sink on the right. A temperature-gap bridge, a solid contact channel, airflow curves, and radiation arcs all come from the same hot-block and room temperatures.

Changing the controls updates the same live state: the hot-block temperature, room temperature, material conductivity, contact quality, surface area, and airflow all update the pathway split, the readout card, the graphs below, compare mode, prediction mode, and challenge checks together.

Graph summary

The temperature-history graph compares the hot block with the fixed room temperature so the shrinking delta T stays visible. The pathway-rates graph compares conduction, convection, radiation, and the total on one shared time axis.

The contact-response graph sweeps only the contact quality, which isolates the conduction path. The contrast-response graph sweeps only the temperature contrast, which is where the stronger radiation curvature becomes most visible.

Keep moving through the concept map.

These suggestions come from the concept registry, so the reason label reflects either curated guidance or the fallback progression logic.

What the energy does nextThermodynamics