List of Topics

SfC Home > Physics > Thermal Energy >

To Heat an Object

by Ron Kurtus

To heat an object or system means to transfer thermal energy from something of a higher temperature to a lower temperature object. This process of energy transfer is called heating the object. Also, feeling heat means sensing the increase in temperature.

An object does not possess "heat". The appropriate term is thermal energy, which may be transferred by conduction, convection, or radiation.

The standard unit of heat or thermal energy measurement is the calorie.

Questions you may have include:

This lesson will answer those questions. Useful tool: Units Conversion



Heat is energy in transit

Heating an object means you are transferring thermal energy from a higher temperature area in order to raise the object's temperature.

An object feels warm or hot if its temperature is higher than your skin. To say something is hot means its temperature is relatively high.

Cooling an object is when you are transferring thermal energy from the object from an another object that is at a lower temperature. You could say you are removing thermal energy from your object.

An object feels cool or cold if its temperature is lower than your skin. To say something is cold means its temperature is relatively low.

Whether heating or cooling, the end result is that the two objects become the same temperature after a period of time. This is called thermal equilibrium.

Heat transfer

Heat energy is transferred from an object of high temperature to one of lower temperature by conduction, convention and radiation. This process is usually called heat transfer or heat flow, although it is the thermal energy that is really being transferred.

(See Heat Transfer for more information on that subject.)

Conduction

Conduction is when materials are in physical contact and kinetic energy is transferred through collisions of their particles, according to the Kinetic Theory of Matter.

(See Kinetic Theory of Matter for more information on that subject.)

Convection

Convection is the movement of thermal energy from one area to another in a liquid or gas.

Radiation

Radiation is when warm or hot matter emits electromagnetic radiation—especially infrared—that is then absorbed by an object at a distance. The absorption heats the second object.

Units of heat

The amount of heat or thermal energy transferred from one object to another can be measured in joules, which is the unit of energy. But more often, you see heat measured in calories. A calorie (cal) is the amount of energy required to raise the temperature of 1 gram of of water by 1° C.

The relationship between joules and calories is: 1 cal = 4.186 J.

Kilocalorie

A kilocalorie (kcal) equals 1000 calories. Transferring 1 kcal of heat to 1 kilogram of water will increase its temperature 1° C. A kilocalorie is also called a Calorie (with a capital "C") by those dealing with food and diets. When you hear that some food has 200 Cal, that means it has the potential of transferring 200 kilocalories of heat energy to the body.

BTU

In the United States, some use the BTU (British Thermal Unit) as a unit of heat transfer. A BTU is defined as the quantity of energy necessary to raise the temperature of 1 lb. of water 1° Fahrenheit. Often the BTU is used to indicate the heat capacity of a home furnace.

Summary

To heat an object means to transfer thermal energy from the higher to lower temperature object. Heat transfer between objects is done by conduction, convection and radiation. The standard unit of heat measurement is the calorie.


Knowledge of science is important to success in life


Resources and references

Ron Kurtus' Credentials

Websites

Physics Resources

Books

(Notice: The School for Champions may earn commissions from book purchases)

Top-rated books on Thermal Energy

Top-rated books on Physics of Heat


Students and researchers

The Web address of this page is:
www.school-for-champions.com/science/
heat.htm

Please include it as a link on your website or as a reference in your report, document, or thesis.

Copyright © Restrictions


Where are you now?

School for Champions

Physics topics

To Heat an Object




Thermal Energy topics

Temperature

Heat transfer

Thermal insulation

Thermodynamics



Let's make the world a better place

Be the best that you can be.

Use your knowledge and skills to help others succeed.

Don't be wasteful; protect our environment.

You CAN influence the world.





Live Your Life as a Champion:

Take care of your health

Seek knowledge and gain skills

Do excellent work

Be valuable to others

Have utmost character

Be a Champion!



The School for Champions helps you become the type of person who can be called a Champion.