1. What is Rate of Cooling?

Definition: The rate of cooling describes how quickly an object's temperature decreases over time, measured in degrees Celsius per second (°C/s).

Purpose: This calculation is essential in thermodynamics, materials science, and engineering to predict cooling behavior of objects.

2. How Does the Calculator Work?

The calculator uses Newton's Law of Cooling approximation:

Where:

• \( \text{Rate} \) — Cooling rate (°C/s)
• \( k \) — Cooling constant (depends on environment)
• \( A \) — Surface area (m²)
• \( \Delta T \) — Temperature difference between object and environment (°C)
• \( m \) — Mass of the object (kg)
• \( c \) — Specific heat capacity (J/kg·°C)

Explanation: The rate is proportional to the surface area and temperature difference, and inversely proportional to mass and specific heat.

3. Importance of Cooling Rate Calculation

Details: Understanding cooling rates helps in material processing, food preservation, electronic cooling, and many industrial processes.

4. Using the Calculator

Tips: Enter all positive values. The default specific heat (4186 J/kg·°C) is for water - adjust for other materials.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical value for k?
A: The cooling constant varies greatly (0.001-10) depending on environment (still air, water flow, etc.) and surface properties.

Q2: How accurate is this approximation?
A: It works well for moderate temperature differences. For large ΔT or complex systems, more advanced models are needed.

Q3: What affects the cooling rate most?
A: The temperature difference (ΔT) has the most significant impact, followed by surface area.

Q4: How do I find specific heat values?
A: Material property tables provide these values (e.g., water=4186, aluminum=900, steel=500 J/kg·°C).

Q5: Can I calculate cooling time with this?
A: This gives instantaneous rate. For total cooling time, you'd need to integrate over the temperature change.