Real Life Applications

## Thermal Properties Of Matter

- Wondering why to study this chapter? Know the real world use of it
1
APPLICATION OF NEWTON'S LAW OF COOLING IN FORENSIC SCIENCE:
One of the major application of Newton's law of cooling can be easily seen in forensic science. Newton's Law of Cooling states that the rate of cooling of an object is proportional to the temperature difference between the object and its surroundings, provided that this difference is not too large. When estimating the time of death, one needs to know the temperature of the surroundings and the temperature of the body at two different times in order to make an accurate estimate. The detectives and forensic scientists note down the temperature of the dead body and the room temperature of the crime scene. The temperature values are put in the mathematical formula derived by Newton's law of cooling and the time of the victim's death can be effectively calculated.
2
EXTINGUISHING FIRE USING BOILING WATER (LATENT HEAT):
Fire extinguishing involves absorption of heat and the absorption of heat in converting boiling water to steam is very much more than the the heat absorbed in heating cold water to the boiling temperature. Boiling water readily converts to steam absorbing enormous amount of heat. It is true that cold water absorbs more heat that hot water, but it takes more time than the cooling effect produce by vaporization of hot water. Also, boiling water absorbs heat in the form of latent heat for the purpose of changing its liquid state to vapors and latent heat of vaporization is quite high for water. So, boiling water can extinguish fire more quickly than ice or cold water.
3
APPLICATION OF THERMAL EXPANSION IN THERMOSTAT SWITCH:
Bimetallic strips used in thermostats work on the principle of thermal expansion. A bimetallic strip is a combination of two different metal strips, usually brass and iron, joined together with rivets. The two metals have different rates of thermal expansion. When a thermostat is used in an electrical circuit, its bimetallic strip gets heated and bends if the temperature in the circuit exceeds a certain limit. Hence the circuit breaks. Since there is no current in the circuit now, the temperature of the strip decreases. The strip gets restored to its original position, and the circuit is completed, allowing current to flow again. Thermostats are used in appliances like geysers, refrigerators, electric irons, air conditioning machines, fire alarms, etc.
4
APPLICATION OF SPECIFIC HEAT IN COOKING UTENSILS:
Substances that hold a small specific heat capacity could be quickly heated up, but it also experiences a wide change in temperature even when only a small amount of heat is supplied. Substances with small specific heat capacity prove to be very useful as material for cooking utensils such as frying pans, pots and kettles because they quickly heat up even when little heat is supplied.
5
APPLICATION OF THERMAL EXPANSION
In anciant time thermal expansion are broadly used to insert a metallic ring over Wooden wheels. This metal expansion process are used in tool making process and, in many more situation. Watch the video to understand its broad application in daily life.
Applications of Thermal Expansion and Contraction of Solids
7 mins