Section 2.1: Temperature
Temperature is a measure of the average kinetic energy of particles in a substance. It quantifies how hot or cold a system is and is fundamental to understanding heat transfer.
Key Concepts:
- Temperature Scales: Celsius (°C), Fahrenheit (°F), Kelvin (K)
- Kelvin Scale: Absolute zero at 0 K (−273.15 °C)
- Conversions:
\( T(K) = T(°C) + 273.15 \)
\( T(°F) = \frac{9}{5}T(°C) + 32 \) - Thermal Equilibrium: When two objects in contact have the same temperature
Example
A scientist records a temperature of 25 °C. Convert this to Kelvin.
\( T(K) = 25 + 273.15 = 298.15 \, K \)
Practice Problems
- Convert 100 °C to Kelvin.
- Convert 0 °C to Fahrenheit.
- At what temperature are Celsius and Fahrenheit equal?
- Why is the Kelvin scale preferred in physics over Celsius?
- A temperature of −40 °C is recorded. Express this in Fahrenheit and Kelvin.