Touch an engine after a ride, and it feels hot. Dip your finger in ice water, and it feels cold. That's a no-brainer! But what if a polar bear, used to freezing Antarctic temperatures, touched the same things? Both might feel hot to a polar bear because it lives in much colder climatic conditions than we do. Hot and cold are correlative terms that can be used to compare how objects feel when they have more or less of a certain kind of energy, which we call heat. What is this heat, where does it come from, and how does it move around our world? Let's explore more!
Heat
Heat energy is called Heat. When an object is very hot, it generally possesses a lot of heat energy; similarly, when the object is cold, it has less heat energy. The things which seem colder such as polar bears and icebergs, have rather more heat energy than you. Every object consists of atoms and molecules. These molecules collide with each other like people in the crowd, and this is known as the kinetic energy of matter.
The Kinetic energy theory helps us to understand what will happen to the energy when we heat something. If you put a vessel full of water on a hot stove, you are going to make the molecules in the water move around more quickly and collide with each other. The more heat we supply, the more molecules move faster, and these molecules start moving apart. Eventually, they collide around so much that they break apart from one another. At that point, the liquid you have been heating turns into a gas, your water becomes vapour and starts evaporating away.
Transmission of Heat:
The heat can be transferred from one place to another in different ways:
Conduction
Conduction mostly happens in a solid-state. All liquids (except mercury) and gases are poor conductors of heat. When a solid heat up, its molecules gain kinetic energy and increase the energy with which they vibrate. Conduction occurs when heat energy travels through a body, passing from one particle to another particle as they vibrate against each other. A good conductor must have particles that are close enough together to collide with sufficient force for energy to be transferred from one place to another.
Convection
Convection is the way in which heat flows through liquids and gases. Take a vessel of cold liquid soup on your stove and put it on the stove. The soup in the bottom of the pan, closest to the heat, warms up quickly and becomes less dense than the cold soup above. The soup which is warmer rises upward, and the colder soup above it comes down to take its place. Pretty soon, you've got a circulation of heat running through the pan, a bit like an invisible heat conveyor, with warming, rising soup and cooling, filling soup. Gradually, the whole pan heats up.
Radiation
Radiation is the way we get heat energy from the sun. This radiation does not require a medium for its transmission such that it can travel through empty space, and this radiation is in the form of electromagnetic energy waves, which travel in a similar way as light or radio waves.
Temperature:
Temperature is a measure that determines the coldness or hotness of an object. Temperature is a measure of the average kinetic energy of the molecule or particles in an object, which is a type of energy associated with motion. But how hot is the object, and how cold is the object? The terms hot and cold are non-scientific terms. If we really want to specify how hot or cold an object is, we must use temperature. For instance, how hot is melted iron? To answer that question, a researcher would measure the temperature of the liquid metal. We will use the term temperature to define the hotness or coldness of an object. A thermometer measures the temperature of an object showing how hot or cold it is. There are different types of thermometers that can measure the temperature of different things. We use thermometers to measure the temperature of our body, the food we consume, the air and many other things. A thermometer can be classified into two types: Analog and Digital Thermometers.
The first law of thermodynamics’ equation form is given below:
ΔEint = ΔQ – ΔW, where ΔEint is the change in internal energy of the system, Q is the work done on the body and W is the work done by the body. Where ΔEint can also be represented as ΔU
The Measure of Temperature:
This scale has the freezing point of water (H₂O) at O℃ and the boiling point of water (H₂O) at 100℃. The temperature in between are divided up into 100 units (degree).
The disadvantages of the Celsius Scale are:
In some case, there may be temperatures below O℃. The pressures and volumes of gases do not change in proportion to Celsius temperature.
This scale has absolute zero as the zero points on its scale. The means of the degree is the same as a Celsius degree. The advantages are:
There are no negative temperatures on this scale.
Pressures and volumes of all the gases will change in proportion to Kelvin temperature.
The absolute zero is 273 degrees below O℃.
To Convert From Celsius Degrees to Kelvin Degrees:
Add 273 to the Celsius degree
For example, the value given in Celsius is 5℃a, the Kelvin value is 278 K.
To Convert From Kelvin Degrees to Celsius Degrees:
Subtract 273 to the Kelvin degree.
For example, the value in Kelvin is 278 K, the Celsius value is 278 – 273 = 5℃.
Figure: A plot of Temperature in Fahrenheit (tf) versus Temperature in Celsius (tc).
To Convert Temperatures from the Fahrenheit Scale to Celsius
To convert from Fahrenheit to Celsius, simply use the following steps.
Take the temperature given in °F and subtract 32
Multiply this number by 5 and then divide the resulting number by 9.
OR
Multiply the number attained from Step 1 by 0.5556 (5/9)
To convert from Celsius to Fahrenheit
To convert temperatures from Celsius to Fahrenheit, apply the following formula
°F = (°C × 9/5) + 32
Temperature Conversion Formula
Are Heat and Temperature the same?
Heat Temperature
Heat and Temperature:
Heat is the energy stored inside an object.
The coldness or hotness of an object is measured by temperature.
An object's temperature cannot tell us how much heat energy it has. It's easy to see, but why not if you think about an iceberg and an ice cube. Both are more or less the same temperature but, because the iceberg has more mass than the ice cube has, it contains billions of more molecules (or particles) and a great deal of more heat energy. An iceberg could even contain more heat energy than a cup of coffee or a red-hot iron bar because of a greater number of molecules present. That's because it is bigger and contains more and more molecules, each of which has some heat energy. The coffee and the iron bar are hotter such that they have a higher temperature, but the iceberg holds more heat because of its mass.
The Difference Between Heat and Temperature
Questions:
1. When the temperature increases, the molecules move ___________
Slower
Faster
Faster and slower
Answer: Faster
2. Temperature is the average ___________ energy of molecules of the matter.
Potential
Kinetic
Mechanical
All of the above.
Answer: Kinetic
3. Convert 15℃ to Kelvin scale.
300 K
288 K
258 K
273 K
Answer: 288 K
4. Methods used for transmission of heat.
Conduction
Radiation
Convection
All of the above
Answer: All of the above
Answer the Following:
1. Define the term heat and temperature?
Ans: Heat is generally a subjective measure of how hot or cold an object is. In scientific terms, however, heat is used to describe the movement of heat energy from one object to another.
Temperature is an objective measure of the heat energy contained in a body. This is a term used to quantify heat.
2. Distinguish between heat and temperature?
Ans: Heat is the process of the transfer of energy from one body to another. It is also often used as a subjective measure of the heat energy contained in a body.
Meanwhile, temperature is an objective measure of the heat energy contained in a body. It is measured in different scales like the Kelvin Scale, Celsius Scale, and Fahrenheit Scale.
3. Explain how to convert Celsius into kelvin and vice versa with an example?
Ans: To convert from Celsius to Kelvin, add 273 to the temperature in Celsius. For example, if you need to convert 2°C to Kelvin, add 2+273 = 275. Therefore, the equivalent temperature in Kelvin would be 275°K
To convert from Kelvin to Celsius, subtract 273 from the number in Kelvin. For example, if you need to convert 300°K to Celsius, subtract 300 - 273 = 27. Therefore, the temperature is 27°C.
FAQs on Difference Between Heat And Temperature
1. What is Heat?
In simple terms, heat is a term used to describe how hot an object is. In physics, heat is a form of energy that determines how hot or cold an object becomes. So if there is a lot of heat in or emitted by an object, when we touch that object, we find it to be hot. When there is an absence of heat, we call that cold.
2. What is Temperature?
Temperature is an objective measure of heat or the lack of heat based on an established scale. In simple terms, it refers to the hotness or coldness of an object or area based on pre-established scales of rating temperature.
For example, when you look up the temperature in your area, you will normally see a number expressed in degrees based on a particular scale. For the temperature of a place or area, the most common scales used are the Celsius scale and the Fahrenheit scale. Another scale that is commonly used in scientific research is the Kelvin scale.
