Newton's Law of Cooling Calculator

Calculate temperature changes over time using Newton's law of cooling formula

Newton's Law of Cooling Calculator

°C
s⁻¹

Material-dependent constant (typically 0.001 to 0.1 s⁻¹)

Cooling Results

34.9°C
Final Temperature
0.1934
Cooling Rate (°/s)

Formula used: T = T∞ + (T₀ - T∞) × e^(-kt)

Parameters: T₀ = 100°, T∞ = 22°, k = 0.015000 s⁻¹

Time elapsed: 2.0 minutes

Cooling Analysis

Temperature dropped by 65.1° in 2.0 minutes
Average cooling rate: 0.5426°/s
ℹ️ Object is still cooling towards ambient temperature

Example Calculation

Coffee Cooling Example

Initial coffee temperature: 100°C

Room temperature: 22°C

Cooling coefficient: 0.015 s⁻¹

Time: 2 minutes (120 seconds)

Calculation

T = T∞ + (T₀ - T∞) × e^(-kt)

T = 22 + (100 - 22) × e^(-0.015 × 120)

T = 22 + 78 × e^(-1.8)

T = 22 + 78 × 0.165

T = 34.9°C

Heat Transfer Mechanisms

1

Conduction

Heat transfer through direct contact

2

Convection

Heat transfer by fluid motion

3

Radiation

Heat transfer by electromagnetic waves

Typical Cooling Coefficients

Water in air0.01-0.05 s⁻¹
Coffee/Tea0.005-0.02 s⁻¹
Metal objects0.02-0.1 s⁻¹
Small objects0.001-0.01 s⁻¹

Physics Tips

💡

Newton's law applies when the object temperature is uniform

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Larger temperature differences lead to faster cooling

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Cooling rate decreases exponentially over time

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Ambient temperature acts as the cooling limit

Understanding Newton's Law of Cooling

What is Newton's Law of Cooling?

Newton's Law of Cooling states that the rate of change of temperature of an object is proportional to the difference between its own temperature and the ambient temperature. This law describes how objects cool down (or heat up) when placed in a different temperature environment.

Key Applications

  • Food and beverage cooling
  • Forensic science (time of death estimation)
  • HVAC system design
  • Industrial process cooling

Mathematical Formula

T = T∞ + (T₀ - T∞) × e^(-kt)

  • T: Temperature at time t
  • T∞: Ambient temperature (final temperature)
  • T₀: Initial temperature
  • k: Cooling coefficient (s⁻¹)
  • t: Time elapsed

Note: The cooling coefficient k depends on the material properties, surface area, and heat transfer mechanism involved.

Cooling Coefficient Calculation

The cooling coefficient can be calculated from material properties using the formula:

k = hA/C

h - Heat Transfer Coefficient

Depends on the heat transfer mechanism (conduction, convection, radiation)

A - Surface Area

The area through which heat is being transferred

C - Heat Capacity

The amount of heat needed to raise temperature by 1 degree