15 Energy & Heat
Resources
- Video to Watch: Mechanical Universe – Episode 45 – Temperature and the Gas Law
- Video to Watch: Mechanical Universe – Episode 46 – The Engine of Nature
- Extra Help: A-Level Physics Tutor
Equations Introduced and Used for this Topic:
- [latex]Q = mc\Delta T[/latex]
- [latex]Q =\pm mL_f[/latex]
- [latex]Q =\pm mL_v[/latex]
Where…
- [latex]Q[/latex] is the heat (energy), measured in joules (J)
- [latex]L_v[/latex] is the latent heat of vaporization, measured in joules/kilograms (J/kg)
- [latex]L_f[/latex] is the latent heat of fusion, measured in joules/kilograms (J/kg)
- [latex]∆T[/latex] is the change in temperature, measured in Celsius (°C) or Kelvin (K)
- [latex]c[/latex] is the specific heat constant, measured in joules/kilograms degrees Celsius (J/kg°C). Specific heat is found by experiment but has a rough value for specific temperature ranges.
- [latex]m[/latex] is the mass of the object or substance being heated/cooled, measured in kilograms (kg)
| Material | Specific Heat | Material | Specific Heat |
|---|---|---|---|
| Aluminum | 900 J/kg°C | Lead | 160 J/kg°C |
| Brass | 384 J/kg°C | Mercury | 139 J/kg°C |
| Copper | 390 J/kg°C | Pyrex | 837 J/kg°C |
| Ethanol | 2400 J/kg°C | Silver | 235 J/kg°C |
| Glass | 840 J/kg°C | Steel | 445 J/kg°C |
| Ice | 2100 J/kg°C | Steam | 2020 J/kg°C |
| Iron | 460 J/kg°C | Water | 4187 J/kg°C |
| Material | Lf (J/kg) | Lv (J/kg) |
|---|---|---|
| Water | 3.34 × 105 | 2.26 × 106 |
| Mercury | 1.18 × 104 | 2.96 × 105 |
| Ethyl Alcohol | 1.05 × 105 | 8.54× 105 |
| Nitrogen | 2.55 × 104 | 1.99 × 105 |
| Oxygen | 1.38 × 104 | 2.13 × 105 |
| Hydrogen | 5.86 × 104 | 4.52 × 105 |
| Helium | 5.23 × 103 | 2 × 104 |
| Material | Tf (°C) | Tv (°C) |
|---|---|---|
| Water | 0 | 100 |
| Mercury | −38.8 | 356.7 |
| Aluminum | 660.3 | 2519 |
| Nitrogen | −210 | −195.8 |
| Oxygen | −218.8 | −183 |
| Hydrogen | −259.1 | −252.9 |
| Helium | −272.2 | −268.9 |
15.1 Specific Heat Capacity
Equations Introduced or Used for this Section:
[latex]Q = mc\Delta T[/latex]
| Material | Specific Heat | Material | Specific Heat |
|---|---|---|---|
| Aluminum | 900 J/kg°C | Lead | 160 J/kg°C |
| Brass | 384 J/kg°C | Mercury | 139 J/kg°C |
| Copper | 390 J/kg°C | Pyrex | 837 J/kg°C |
| Ethanol | 2400 J/kg°C | Silver | 235 J/kg°C |
| Glass | 840 J/kg°C | Steel | 445 J/kg°C |
| Ice | 2100 J/kg°C | Steam | 2020 J/kg°C |
| Iron | 460 J/kg°C | Water | 4187 J/kg°C |
Heat and Temperature
- Extra Help: Introduction to Thermal Physics
- Extra Help: Temperature and Thermometers
- Extra Help: Thermometers as Speedometers
- Extra Help: What is Heat
- Article to Read: Finally, We Know What Killed Sea Life in The Deadliest Mass Extinction in History
- Article to Read: Researchers find Americans set their thermostat to match African environmental temperatures
Specific Heat Capacity (Q) – or heat capacity – refers to the ability of a system or body’s capability of absorbing or losing energy (heat energy) without changing its