• Tue. Apr 23rd, 2024

NEWTON LAW OF COOLING: Have you ever noticed why hot milk or hot water kept cool faster than warm water or milk? Well, there’s a scientific reason behind it! Newton was the first person who study the connection between the heat lost by an object or a body to its surroundings. This study by Newton is called NEWTON LAW OF COOLING.

In this blog, you will learn about this law by Newton. Don’t skip any information in this article to learn everything you must know!


It is a fundamental law that tells us how much heat transfer is done by an object or a body to its surroundings. Moreover, it states that the rate of heat transferred is directly proportional to the difference in the body’s temperature and the outside temperature. In simpler words, if the difference between the body’s temperature and the temperature of the surroundings if greater, the heat produced from the body will be more. Similarly, if the difference is low, less heat will be lost.

Additionally, it is derived from Stefan’s law of radiation. The difference between these two laws is that Stefan’s law of radiation can be applied to any black body given at any temperature. Whereas, Newton’s law can only be effective when the difference between the body and surrounding temperature is low.


“The rate of heat loss from a body is directly proportional to the difference in temperature between the body and its surroundings, given that the temperature differential is not large.”


The limitations of this law by Newton are as follows-

  • Heat lost by a body or an object is in the form of radiation.
  • If the temperature of the surroundings keeps on changing during the cooling of the body, this law will not be in effect.
  • The law will only be valid if the difference between the body and surroundings is low.


Newton’s law of cooling comes with a formula which is –

T(t) = Ts + (To – Ts) e-kt  

In this formula,

  • T (t) is the temperature of an object/body at a particular time.
  • t is the time given.
  • Ts is the surrounding’s temperature.
  • To  is the initial temperature of the object/body
  • k is the cooling constant.
  • It is calculated in Celsius.


  • Cooling of a beverage, given an ambient temperature.
  • Process of ice cream melting
  • Process of ice melting


This law can be applied for examination in the fields of engineering and technology, forensic science as well as culinary arts. How this law is used in these fields is explained further –

Engineering and Technology

This law is applied while designing cooling electronic devices used for temperature control. This law helps in determining the appropriate temperature and acts as a guiding principle.

Forensic science

This is one of the most important fields in which this law is applied. Newton’s law is used to estimate the time of death of a particular body. Valuable assessments are done based on temperature of the deceased body and its surroundings at that time. Therefore, this law proves helpful in forensic investigations.

Culinary arts

Determining safe temperatures for various types of food is an important thing done by food scientists and chefs. This process uses Newton’s law to regulate the temperature.

Moreover, have you noticed that your tea or coffee does not take the same time to cool down when poured in different material cups? This is because the process of cooling down is based on the temperature of the surroundings. The material of different cups may regulate the time taken by the beverage to cool down.

Therefore, through this observation, we can see that not only in above mentioned fields of study, but Newton’s law also plays its role in day-to-day life.

You must have heard of extremely comfortable houses and the temperature inside the houses is always perfect. To make such houses, understanding the concept of heat exchange between objects is very important. This law may also help in making a comfortable home.


Newton’s Law of Cooling refers to the study which examines the rate of heat exchange between an object or a body and its surroundings. This law can only be applied when the difference between the temperature of both the elements in low. The study of heat loss in a body was first done by Newton. It is applied in fields like forensic science, engineering and technology and culinary science. This law by Newton can also be used to make comfortable homes encouraging environmental sustainability.

Moreover, In this article, we have mentioned everything about this law including the mathematical formula. Hence, we hope you now know why your beverage takes different amounts of time to cool down in different situations. So grab your coffee and notice the changes! This is all for this article. Enjoy your day.

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