Difference Between Heat And Temperature

Difference Between Heat And Temperature - Definition and Comparison

Introduction 


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, 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 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 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 vapor 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 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 which 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 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 the 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 which 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 = Q – W, 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:

The Celsius Scale (°C):


This scale has the freezing point of water (H2O) at OoC, and the boiling point of water (H2O) at 100o C. The temperature is in between are divided up into 100 units (degree).

The disadvantages of the Celsius Scale are: 
 
In some case, there may be temperatures below OoC. The pressures and volumes of gases do not change in proportion to Celsius temperature. 

The Kelvin Scale (K): 


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 Oo C. 

To convert from Celsius degrees to Kelvin degrees:


Add 273 to the Celsius degree 

For example, the value given in Celsius in 5o C, 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 = 5o C.



Figure: A plot of Temperature in Fahrenheit (tf) versus Temperature in Celsius ( tc)

Temperature conversion formula

Tc = ( Tf-32)Converts Fahrenheit to Celsius
TF = TC + 32 Converts Celsius to Fahrenheit
TK = TC + 273Converts Celsius to Kelvin
TC = TK - 273Converts Kelvin to Celsius


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 for 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 have a higher temperature, but the iceberg holds more heat because of its mass.

    Heat( Q )Temperature( T )
    1 Heat is the energy stored inside an object 1 Coldness or hotness of an object is measured by Temperature
    2 The SI unit of heat is Joules 2 The SI unit of temperature is Kelvin
    3The amount of heat energy contained in an object depends on its mass, temperature, and material which is the specific heat capacity.3 The Temperature of a body depends on the average kinetic energy of its molecules or particles.
    4 The Heat can be measured using the principle of calorimetry or the principle of the method of mixtures.4 The temperature is measured using the thermometer.
    5 Two bodies that have a similar amount of heat energy can differ in their temperature5 Two bodies at a similar temperature can contain different amounts of heat energy.
    6 When two bodies are in contact, the total amount of heat energy is the sum of the heat energy of each object. 6 If two objects are at completely different temperatures are kept in contact, the resultant temperature will be the temperature between the two temperatures.
    7 Heat has the ability to do work. 7 Temperature can be used only to measure the degree of heat.
    8 Heat is the measure of how many molecules are in an object multiplied by how much energy each molecule possesses. 8 Temperature is related to how fast the molecules move within the object.
    9 The heat flows from hotter bodies to colder bodies. 9 The temperature increases when heated and it decreases when cooled.


    Questions:


  • 1. When the temperature increases, the molecules move ___________

  • • Slower

  • • Faster

  • • Faster and slower


  • 2. Temperature is the average ___________ energy of molecules of the matter

  • • Potential

  • • Kinetic

  • • Mechanical

  • • All of the above


  • 3. Convert 15o C to Kelvin scale

  • • 300 K

  • • 288 K

  • • 258 K

  • • 273 K

  • 4. Methods used for transmission of heat

  • • Conduction

  • • Radiation

  • • Convection

  • • All of the above


  • Answer the following:


  • 1. Define the term heat and temperature?

  • 2. Distinguish between heat and temperature?

  • 3. Explain how to convert Celsius into kelvin and vice versa with an example?