Newton's Law of Cooling:
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Newton's Law of Cooling describes the rate at which an object cools when placed in a surrounding environment with a different temperature. It states that the rate of heat loss of a body is proportional to the difference in temperatures between the body and its surroundings.
The calculator uses Newton's Law of Cooling equation:
Where:
Explanation: The equation models exponential decay of temperature difference between an object and its surroundings over time.
Details: This law is fundamental in thermodynamics and has practical applications in food cooling, forensic science (estimating time of death), engineering cooling systems, and climate control.
Tips: Enter all temperatures in Kelvin, cooling constant in reciprocal seconds, and time in seconds. Ensure cooling constant is positive and time is non-negative.
Q1: What is the cooling constant (k)?
A: The cooling constant depends on the object's material, surface area, and the surrounding medium. It represents how quickly the object cools.
Q2: Can I use Celsius or Fahrenheit instead of Kelvin?
A: Yes, but all temperatures must use the same scale. The equation works with temperature differences, so the scale is consistent.
Q3: What are typical values for the cooling constant?
A: Cooling constants vary widely depending on the situation. For a hot cup of coffee in room air, k might be around 0.01-0.1 min⁻¹.
Q4: When is Newton's Law of Cooling not accurate?
A: The law assumes constant ambient temperature and may be less accurate for very large temperature differences, forced convection, or phase changes.
Q5: How is this different from exponential decay?
A: Newton's Law of Cooling is a specific application of exponential decay to temperature differences between an object and its environment.