Heat is a form of energy, heat is also known as calor. As with other types of energy, heat energy can also move from one substance to another, and can change into other forms of energy.
Transfer of heat or calor can occur in various objects such as solids, liquids and gases. This heat transfer occurs due to temperature differences. Heat moves from an object with a higher temperature to an object with a lower temperature.
An object will become hot if it is energized. In physics, heat has the same unit as other forms of energy, namely the joule (j) and is denoted by Q, the other unit is cal (calorie). The ratio between cal and joule is:
1 cal = 4.2 joules
1 joule = 0.24 cal
If a high temperature object is in contact with a low temperature object, the temperature will drop and vice versa. This is due to the nature of the heat that will move from an object with a high temperature to an object with a low temperature.
Before the 17th century, scientists thought of heat as a substance that can move from a high temperature to a lower temperature. but when the object that gets the heat is weighed it turns out that its mass does not change, then the heat is expressed as energy not a substance, because matter must have mass.
Sources of Energy From Heat
Heat or calor in an object can come from various sources, any object that can produce heat is called a source of heat energy. Here are some sources of heat energy.
1. The Sun
The Sun is a very large source of energy and is the largest source of heat and light energy for the earth. In the sun there is always a fusion reaction which is a chain reaction of merging hydrogen atomic nucleir into helium atomic nucleir in very large quantities, resulting in very high heat. A small part of the heat energy from this reaction reaches the earth.
2. Fuel
Fuel can produce energy from heat which is useful for moving objects. An example of a fuel is derived from petroleum.
After going through a petroleum processor, it produces gasoline, avtur, kerosene, diesel, and so on. Gasoline, for example, is used to drive industrial machines or engines in motorized vehicles.
3. Friction
Two objects that touch can cause friction, and friction will produce heat. If this friction is carried out or occurs repeatedly, the heat energy produced will be even greater.
The roughness of rubbing objects also affects the amount of heat energy produced, the rougher the object, the greater the heat that occurs.
Early humans made fire by rubbing wood or stone continuously to cause sparks.
Friction that produces heat does not only occur in friction between solid objects, friction between solid objects and gas objects can cause heat and even flames.
For example, when a meteor falls to earth, the friction between the meteorite and the atmosphere produces a flare of fire which often results in the meteorite being burned.
4. Electricity
Another source of heat energy is electricity. Electricity is generated by generators, batteries, batteries, etc. Electrical energy is converted into heat energy, for example by various household appliances, such as electric stoves, irons, microwave ovens, and so on.
5. Food
Food is a very important source of energy for living things. Food that has been digested will produce chemical energy which is then converted into heat energy by the body.
Heat Transfer
In addition to being able to move due to the influence of temperature, namely from high temperatures to low temperatures, heat energy can also move through various intermediaries, namely through solids, liquids and gases. This heat transfer can occur by:
a. Conduction
Conduction is the transfer of heat that is not accompanied by the movement of particles of the substance. For example, if we stick the end of a piece of iron to a bonfire, while holding the other end, our hands will feel hot even though there is no fire on our hands.
Conduction events usually only occur in solids. Each solid has a different ability to conduct heat, metal is a good conductor while wood is a poor conductor.
b. Convection
Convection is the transfer of heat energy accompanied by the movement of particles. Convection events usually occur in gases and liquids.
Examples of convection events are when we boil water or when there are sea breezes and land breezes.
A sea breeze is a wind that blows from the sea to the land, this happens because the temperature on land is higher than the temperature at sea level, while the air pressure on the land is lower so that air flows from the sea to the land and heat energy moves from the land to the ocean. In the event of a land breeze, the opposite happens.
c. Radiation
Radiation is the transfer of heat energy that does not pass through an intermediary. An example of radiation is the radiant heat of the sun during the day. During the day we feel the sun's heat because the sun's heat radiates directly to the earth without an intermediary.
Radiation also occurs when we surround a bonfire we feel warm because the heat from the bonfire hits us directly.
The Impact of Thermal Energy
Everything that exists in this world such as energy must have an impact due to it. Heat or heat has an effect on the object it is subjected to. Among them are changing the shape of objects, changing the temperature of objects and changing the size of objects.
Heat changes the shape of an object
An object that is subjected to heat will experience a change in shape. Changes in the shape of the object are as follows:
a. Evaporation
The change of state from a liquid to a gas is called evaporation. Evaporation occurs when a liquid is exposed to high enough heat. An example is salt farmers who make salt in coastal ponds.
b. Condensation
Events condensationis the opposite of evaporation, ie changing the gas to a liquid. An example is the formation of water droplets on the leaves in the morning.
c. Melting
Melting is the change of a solid into a liquid. Melting occurs because the substance receives heat energy. For example, an ice cube left in the hot sun will melt/melt.
d. Freezing
The change from a liquid to a solid is known as freezing. Freezing occurs because the liquid releases heat energy so that its temperature decreases. For example, water that is put in the freezer will freeze.
e. Sublimation
Sublimation is the change of a solid to a gas. This change also requires heat energy. An example is the camphor stored in the wardrobe over time will run out.
f. Expansion
Expansion is an increase in the size or volume of an object due to exposure to heat energy. Expansion can occur in solids, liquids and gases. An example is the use of mercury in a thermometer.
Well, now you know the benefits of heat energy in life. Hopefully the information presented is useful for readers.