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🔥 Heat and Thermodynamics

Learn heat, temperature, heat transfer, thermal expansion, specific heat, latent heat and the laws of thermodynamics with animated activities and quizzes.

Heat Temperature Thermodynamics Conduction Radiation

📌 What is Heat?

Heat is a form of energy that flows from a hotter body to a colder body due to temperature difference. Thermodynamics studies heat, work, temperature and energy transformations.

🌡️ Temperature

Temperature tells the degree of hotness or coldness of a body.

🔥 Heat

Heat is energy transferred because of temperature difference.

⚙️ Thermodynamics

Thermodynamics studies the relation between heat, work and energy.

🌈 5W-1H + 1U

🔴 What: Heat is energy that flows from a hot body to a cold body.

🟠 Why: Heat explains warming, cooling, melting, boiling and energy transfer.

🟡 When: Heat transfer occurs when two bodies have different temperatures.

🟢 Where: Heat transfer occurs in kitchens, engines, weather, machines and living bodies.

🔵 Who: Students, engineers, doctors, scientists and mechanics use thermodynamics.

🟣 How: Heat transfers by conduction, convection and radiation.

⚫ 1U: Heat is not the same as temperature. Heat is energy, while temperature measures hotness.

🔥 Modes of Heat Transfer

Conduction

Heat transfer through direct contact.

Example: A metal spoon becomes hot in tea.

Convection

Heat transfer by movement of fluids.

Example: Hot air rises and cool air sinks.

Radiation

Heat transfer without a medium.

Example: Heat from the Sun reaches Earth.

Animated Heating Demo

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Heat energy flows from the flame to the pan. The pan becomes hot and can transfer heat to food or water.

Animated Thermometer

As temperature increases, the liquid level in the thermometer rises.

⚙️ Thermodynamics

Animated Gas Piston

Heating a gas can increase its pressure or make it expand.

When gas is heated, its particles move faster and collide more strongly with the piston, producing expansion or pressure change.

Q = mcΔT

Q = mL

Energy cannot be created or destroyed

Concept	Meaning	Example
Specific Heat Capacity	Heat required to raise temperature of 1 kg substance by 1°C	Water has high specific heat capacity
Latent Heat	Heat used to change state without changing temperature	Ice melting at 0°C
Thermal Expansion	Increase in size due to heating	Railway tracks need gaps
First Law	Energy is conserved	Heat can become work in an engine
Second Law	Heat naturally flows from hot to cold	Hot tea cools down

🧮 Heat Calculators

Calculate Heat Energy

Use: Q = mcΔT

Calculate Latent Heat Energy

Use: Q = mL

Convert °C to K

Use: K = °C + 273

✅ Heat and Thermodynamics Quiz

1. Heat is a form of: Energy Mass Volume

2. Heat naturally flows from: Hot to cold Cold to hot always Nowhere

3. Heat transfer through direct contact is: Conduction Radiation Reflection

4. Heat transfer by movement of fluids is: Convection Conduction Friction

5. Heat from the Sun reaches Earth by: Radiation Conduction Only convection

6. Formula for heat energy is: Q = mcΔT Q = m + c Q = T/c

7. Formula for latent heat energy is: Q = mL Q = m/L Q = L/m

8. Temperature tells: Degree of hotness or coldness Amount of matter Only size

9. Thermal expansion means: Expansion on heating Cooling only Breaking always

10. First law of thermodynamics is related to: Conservation of energy Colour change Shape only

🧠 HOTS Questions

1. Why does a metal spoon become hot in tea?

Heat travels through the metal spoon by conduction.

2. Why does hot air rise?

Hot air expands, becomes less dense and rises. Cooler air sinks to take its place.

3. Why can heat from the Sun travel through space?

Heat from the Sun reaches Earth by radiation, which does not require a material medium.

4. Why are gaps left in railway tracks?

Metals expand on heating, so gaps are left to prevent bending of tracks during hot weather.

5. Why does ice absorb heat while melting but temperature stays constant?

The absorbed heat is used as latent heat to change the state from solid to liquid, not to raise temperature.