Difference Between Temperature and Heat

Summary

This video delves into the concepts of temperature and heat, elucidating their differences and measurements. It explains temperature as the average kinetic energy of molecules, while heat is the total kinetic energy. The script clarifies that temperature measures molecular agitation and heat is energy transfer, using examples to illustrate their distinct behaviors. It also covers temperature scales, measurement instruments like thermometers and radiosondes, and introduces specific heat, sensible heat, and latent heat, crucial for understanding meteorological phenomena.

Takeaways

• 🌡️ Temperature is a measure of the average kinetic energy of the molecules in a substance, reflecting how fast they move on a microscopic level.
• 🔥 Heat is a form of energy and is the total kinetic energy of all the molecules in a body or substance, not just the average.
• 💧 The relationship between temperature and heat is not always direct; a substance with a lower temperature can have more heat if it has more molecules.
• ⚖️ Temperature is an intensive property, making it independent of the amount of substance, whereas heat is an extensive property, dependent on the quantity of the substance.
• 🌡️🔥 The concept of temperature does not apply to a single molecule but makes sense when considering a large group of molecules.
• 🌡️➕ Heat transfer occurs from a body at a higher temperature to one at a lower temperature until thermal equilibrium is reached.
• 🌡️🌡️ Different temperature scales are used, including Fahrenheit, Celsius, and Kelvin, each with specific references to absolute zero and the points at which water freezes and boils.
• 🌡️📏 Thermometers are used to measure temperature, with different types such as mercury, electrical resistance, infrared, and thermocouple thermometers.
• 🌡️📈 Thermographs record temperature changes over time, helping to analyze and predict weather conditions.
• 🌡️🏠 Stevenson screens protect thermometers and thermographs from environmental influences, ensuring accurate air temperature readings.
• 🌡️🎈 Radiosondes attached to weather balloons are used to measure temperature at different altitudes, with modern models often incorporating GPS for accurate tracking.
• 🔥⚖️ Specific heat capacity is the amount of heat required to raise the temperature of a substance by one degree Celsius and varies between materials.
• 🔥💧 Sensible heat is the heat that increases the temperature of a substance, while latent heat is the heat absorbed or released during a change of state without a change in temperature.

Q & A

What is the primary difference between temperature and heat?

Temperature is the average kinetic energy of the molecules in a substance, indicating how fast the molecules are moving. Heat, on the other hand, is the total sum of the kinetic energy of all the molecules in a body or substance, representing the transfer of thermal energy.

How does the internal energy of a substance relate to its temperature?

The internal energy of a substance, which includes the kinetic energy from the movement of its molecules, is directly related to its temperature. The faster the molecules move, the greater the internal energy and thus the higher the temperature.

Why is it not accurate to associate temperature with the movement of a single molecule?

Temperature is an average measure of the kinetic energy of a large group of molecules. It does not make sense to apply the concept of temperature to a single molecule because temperature is a macroscopic property that emerges from the collective behavior of many molecules.

What are the three most common temperature scales, and how are they related?

The three most common temperature scales are Fahrenheit, Celsius, and Kelvin. They are related in that they all measure temperature but have different reference points and increments. For example, absolute zero is 0 K (Kelvin), -273°C (Celsius), and -459°F (Fahrenheit).

What is the significance of absolute zero?

Absolute zero is the theoretical limit of temperature where molecular motion ceases completely, representing the lowest possible temperature. It is defined as 0 Kelvin, -273.15 degrees Celsius, and -459.67 degrees Fahrenheit.

How does the concept of specific heat relate to the heat capacity of a material?

Specific heat is the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius. Heat capacity, on the other hand, is the total heat energy required to raise the temperature of an entire body or substance by one degree Celsius. Specific heat is a property of a material, while heat capacity depends on both the material and its mass.

What is the difference between sensible heat and latent heat?

Sensible heat is the heat that causes a change in temperature of a substance. Latent heat, however, is the heat absorbed or released by a substance during a phase change (like melting or vaporization) at a constant temperature, without changing the temperature of the substance.

Why does heat transfer occur, and what is the condition for it to stop?

Heat transfer occurs due to a temperature difference between two bodies, moving from the body at a higher temperature to the one at a lower temperature. It stops when thermal equilibrium is reached, meaning both bodies have the same temperature and no more net heat transfer occurs.

What is a thermograph, and how does it differ from a thermometer?

A thermograph is an instrument used to record temperature changes over time, often using a moving paper strip. It differs from a thermometer, which measures the temperature at a specific point in time. A thermometer provides an instantaneous temperature reading, while a thermograph tracks temperature trends.

How are thermometers protected from environmental factors when measuring air temperature?

Thermometers are often placed inside a Stevenson screen or instrument shelter, which is a specially designed structure that shields the instruments from direct solar radiation, precipitation, and surface heating. This ensures accurate air temperature readings by minimizing the influence of these environmental factors.

Outlines

00:00

🔍 Understanding Temperature and Heat

This paragraph introduces the concepts of temperature and heat, explaining the common misconception that temperature is a direct measure of how hot or cold something feels. It delves into the scientific definition of temperature as the average kinetic energy of the molecules in a substance, highlighting the microscopic motion of water molecules as an example. The paragraph clarifies that temperature measures the degree of molecular agitation and that it only makes sense when considering a large group of molecules. It contrasts temperature with heat, which is the total kinetic energy of all molecules in a substance, and uses practical examples to illustrate the differences and relationships between the two concepts.

05:01

🌡️ The Dynamics of Temperature and Heat

The second paragraph explores the relationship between temperature and heat further, emphasizing that they are not always directly proportional. It uses the analogy of a cup of coffee versus the ocean to illustrate that a substance with a lower temperature can have more heat due to the greater number of molecules. The paragraph also discusses how heat transfer occurs from a higher temperature body to a lower one until thermal equilibrium is reached. It introduces the concept of absolute zero and explains the units of measurement for temperature, including Fahrenheit, Celsius, and Kelvin, and their reference points. The paragraph concludes with a brief mention of thermometers and thermographs as instruments for measuring and recording temperature.

10:02

🌡️➕ Measuring Temperature and Heat

This paragraph focuses on the practical aspects of measuring temperature and heat. It describes the Stevenson screen, an instrument shelter that protects temperature-measuring devices from external influences to ensure accurate readings. The paragraph also explains how radiosondes attached to weather balloons are used to measure temperature at different altitudes. The discussion then shifts to measuring heat, introducing the joule as the standard unit and the calorie as a practical unit for measuring the energy required to change the temperature of a substance. The concept of specific heat, which varies among materials, is introduced, and its relation to heat capacity is explained. The paragraph concludes with a table of specific heats for different substances and a practical example demonstrating how materials with different specific heats respond to heat input.

15:05

🔥 The Role of Sensible and Latent Heat

The final paragraph discusses the distinction between sensible and latent heat. Sensible heat is the heat that raises the temperature of a substance, whereas latent heat is the heat absorbed or released during a change of state without a change in temperature. The paragraph uses the example of an ice cube being heated to explain how sensible heat increases temperature until the substance reaches its phase change point, at which point latent heat takes over. The process of the ice cube melting, water boiling, and water vaporizing illustrates the transition between sensible and latent heat. The summary of this concept is crucial for understanding meteorological phenomena, and the paragraph ends with an invitation for viewers to engage with the content and look forward to future videos on the topic.

Keywords

💡Temperature

Temperature is defined as the average kinetic energy of the molecules in a body or substance, which indicates how hot or cold an object is. In the video, it is explained that temperature measures the degree of agitation of the molecules, with higher temperatures corresponding to faster molecular movement. The concept is essential in understanding the differences between temperature and heat, as well as in various meteorological phenomena.

💡Heat

Heat, in the context of the video, refers to a form of energy that can be thought of as the sum of the kinetic energy of all the molecules in a body or substance. It is distinct from temperature, as heat involves the total energy transfer, not just the average kinetic energy per molecule. The script uses the concept of heat to explain thermal energy transfer, such as when heat is transferred from a body at a higher temperature to one at a lower temperature until thermal equilibrium is reached.

💡Internal Energy

Internal energy is the total energy contained within a system, which includes the kinetic and potential energies of its molecules. The script explains that internal energy is not only present in water but in any body or substance, and it is related to the continuous movement of molecules at the microscopic level. This concept is foundational in understanding temperature, as temperature is the average of the kinetic energy derived from this internal motion.

💡Kinetic Energy

Kinetic energy is the energy of motion, and in the video, it is associated with the movement of molecules within a substance. The script clarifies that the faster the molecules move, the more kinetic energy they possess. This is directly related to temperature, as temperature is essentially the average of this kinetic energy, indicating the intensity of molecular motion.

💡Thermal Energy

Thermal energy, as mentioned in the script, is synonymous with heat energy and refers to the total energy contained within a substance due to the motion of its molecules. It is an important concept when discussing the transfer of heat between different bodies, as it encompasses the total sum of kinetic energy of the molecules, which is distinct from the average kinetic energy measured by temperature.

💡Thermodynamics

Thermodynamics is the study of the relationships between heat and other forms of energy in a system. The video references the laws of thermodynamics, particularly the principle that heat always transfers from a body at a higher temperature to one at a lower temperature, until thermal equilibrium is achieved. This principle is crucial for understanding heat transfer processes.

💡Conduction

Conduction is one of the methods of heat transfer discussed in the video, where heat moves through a substance by direct contact between particles. It is a fundamental concept in understanding how heat travels within solids and is an essential part of the overall heat transfer process, which also includes radiation and convection.

💡Thermometer

A thermometer is an instrument used to measure temperature. The script mentions different types of thermometers, such as metallic mercury and electrical resistance thermometers, which are commonly used in meteorology and aviation. Thermometers are vital tools for monitoring temperature changes and are often placed in Stevenson screens to ensure accurate air temperature readings.

💡Specific Heat

Specific heat is defined as the amount of heat required to raise the temperature of a unit mass of a substance by one degree Celsius. The video uses specific heat to explain how different materials require varying amounts of heat to change their temperature. It is a key concept in understanding material responses to heat and is directly related to the heat capacity of a substance.

💡Heat Capacity

Heat capacity is the ability of a material to absorb heat without significantly changing its temperature. In the video, it is contrasted with specific heat, with the former referring to the overall heat absorption capacity and the latter to the heat required for a one-degree temperature change. The script illustrates this concept by comparing the heat capacity of water to that of iron, showing how water can absorb more heat with less temperature change due to its higher heat capacity.

💡Latent Heat

Latent heat is the heat absorbed or released by a substance during a change of state at constant temperature. The video explains that latent heat is 'hidden' within the substance during state changes, such as the transition from solid to liquid or liquid to gas. It is a critical concept for understanding phase changes and is distinct from sensible heat, which is used to increase the temperature of a substance.

Highlights

Temperature is a measure of the average kinetic energy of the molecules in a substance, indicating how hot or cold it is.

Internal energy exists in all substances and is related to the microscopic motion of molecules.

Heat is the sum of the kinetic energy of all molecules in a substance, different from the average kinetic energy indicated by temperature.

A practical example illustrates the difference between temperature and heat, showing that a larger amount of a substance at a lower temperature can have more heat.

Heat transfer occurs from a higher temperature body to a lower one until thermal equilibrium is reached.

Different methods of heat transfer include conduction, radiation, and convection, to be discussed in more detail in a future video.

Absolute zero is the lowest possible temperature, at which point molecules have no kinetic energy.

The most common temperature scales are Fahrenheit, Celsius, and Kelvin, with absolute zero as a reference point.

Thermometers are instruments used to measure temperature, with different types for various applications.

A thermograph records temperature changes over time, useful for predicting weather conditions.

Stevenson screen is used to protect temperature-measuring instruments from external influences for accurate readings.

Radiosondes attached to weather balloons are used to measure temperature at different altitudes.

Heat can be measured in joules or calories, with a calorie being the amount of energy to raise the temperature of one gram of water by one degree Celsius.

Specific heat is the amount of heat required to raise the temperature of a substance by one degree Celsius.

Heat capacity is the ability of a substance to absorb heat without changing its temperature significantly.

Sensible heat is the heat that increases the temperature of a substance, while latent heat is used for state changes at constant temperature.

The process of heating an ice cube demonstrates the transition from sensible to latent heat as it melts and then boils.

Transcripts

hi welcome to Aviation theory in this

video we will talk about temperature and

heat what they are what are their main

differences their units of measurement

among other characteristics

so let's get started

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let's start by looking at what is

temperature

according to our daily experience we

could say that this is a measure of how

cold or how hot an object or substance

is

this way if it is very hot we say that

it has a high temperature and if it is

very cold we say that it has a low

temperature

now at first glance this seems to be

correct but this definition is far from

the real concept of temperature

to understand this better let's look at

the following example here we have a

glass of water at rest which means that

at a macroscopic level the water does

not appear to be moving

however if we observe water at the

microscopic level we will realize that

in fact the water molecules are in

constant motion colliding with each

other

this continuous movement of the

molecules at the microscopic level is

known as internal energy and it is not

only present in water but in any other

body or substance

now as we already know energy in the

form of movement is known as kinetic

energy which is expressed by means of

the translation rotation or vibration of

the molecules

so with this in mind the molecules of a

certain object or substance can move

rotate and vibrate more rapidly or more

slowly depending on their internal

energy

this way if they move slowly then we say

that they have less kinetic energy well

if they move faster it means that they

have more kinetic energy

now understanding all this we can now

move on to the actual concept of

temperature and it is that temperature

is the average of the kinetic energy of

the molecules of a body or substance

in simple words this means that the

faster the molecules of a body move the

higher its internal energy and thus the

higher its temperature

this way we can also say that

temperature measures the degree of

agitation of the molecules of a body or

substance now it is important to clarify

that we say that the temperature is the

average kinetic energy since within the

same substance not all molecules move in

the same way as there may be molecules

that move faster than others

so in this order of ideas if we analyze

a single molecule the concept of

temperature makes no sense it only makes

sense if we analyze a large group of

molecules at the macroscopic level

so now that we know what is temperature

let's move on to the concept of heat

heat in essence is a form of energy and

we can think of it as the sum of the

kinetic energy of all the molecules of a

body or substance

so unlike temperature we are no longer

talking about the average energy of each

molecule but rather the sum of the

energy of all molecules

now technically what we have just said

corresponds to the concept of thermal

energy or heat energy while heat as such

refers more to the transfer of that

thermal energy but for the sake of

Simplicity in this explanation we will

use these terms interchangeably

now so far we may still have some

confusion about the difference between

temperature and heat so let's look at a

couple of practical examples suppose we

have here two containers with the same

amount of water however the difference

is that the water in container a has a

temperature of 20 degrees Celsius and

the water in container B is at 70

degrees Celsius

with this it is evident that in average

the water molecules in container B are

moving faster than in container a hence

its higher temperature

but what happens with heat which of them

contains more heat

well since the amount of water is the

same in both cases it is evident that if

we sum up the kinetic energy of each

individual molecule the water in

container B will also have more heat

than container a

now this example was kind of intuitive

as we normally associate higher

temperature with more heat and vice

versa but let's look at this other

situation

here we have water in two containers at

the same temperature

the difference is that container a now

contains 100 liters and container B only

10 liters

in this case the average kinetic energy

is the same in both containers and

therefore their temperature is the same

however if we sum up the energy of each

individual molecule since container a

has more water molecules then it will

have much more heat than container B

so as we could see although temperature

and heat are related Concepts there is

not always a direct relationship between

them in fact a substance with a lower

temperature may have more heat than one

with a higher temperature

a clear example of this is for example

if we compare the temperature and heat

of a cup of coffee with the ocean in

this case although the ocean has a lower

temperature than a cup of coffee since

it contains many more molecules this

means that it has much more heat

in fact the large amount of heat

contained in the ocean is capable of

generating violent atmospheric phenomena

such as hurricanes

so having all this clear let's look at

the following example here we have two

containers with different amounts of

water but at the same temperature now

let's say that we expose both containers

to an external heat Source in this way

after a certain time say five minutes it

is logical to think that the temperature

of the water in both cases will have

increased

however the thing is that in container B

the temperature increased by 20 degrees

which is a lot while in container a it

only increased a couple of degrees

this happened because in container a the

incoming heat had to be distributed over

the 100 liters of water which increases

the average kinetic energy of the system

very little

while on the other hand in container B

the same amount of heat was distributed

over only 10 liters of water which

increased the average kinetic energy of

the system a lot

now it is important to note that in this

example he is being transferred from the

bonfire to the water and the thing is

that heat can be transferred from one

body to another only if they have

different temperatures

this way and according to the laws of

thermodynamics heat is always

transferred from a body at a higher

temperature to a body at a lower

temperature

this heat transfer will take place until

thermal equilibrium is reached

this thermal equilibrium means that both

substances or objects reach the same

temperature and therefore the heat

transfer stops

this heat transfer can occur by means of

different processes specifically

conduction radiation and convection but

we will talk about them in more detail

in a future video

now at this point you might be wondering

what happens if a body loses all its

heat

well in that case its molecules will not

move or vibrate at all since they will

have lost all of their kinetic energy as

we can see in this example

in this situation we say that the body

has reached the temperature of absolute

zero which by definition is the lowest

possible temperature

so having seen this let's move on to the

units of measurement of temperature

although there are different scales the

most commonly used are Fahrenheit

Celsius and Kelvin

now normally the freezing and boiling

points of water as well as the absolute

zero are used as a reference to compare

these scales

according to this absolute zero is

represented by zero Kelvin minus 273

degrees Celsius and minus 459 degrees

Fahrenheit

the freezing point of water is

represented by 273 Kelvin zero degrees

Celsius and 32 degrees Fahrenheit

and finally the boiling point of water

is represented by 373 Kelvin 100 degrees

Celsius and 212 degrees Fahrenheit

here we can see the most commonly used

conversion factors between these units

as we can see in the formula at the

bottom the relationship between Kelvin

and Celsius is quite simple as they have

a direct relation with a difference of

273 units while on the other hand the

conversion from Fahrenheit to Celsius

and vice versa is a bit more complex as

it involves using fractions however we

can also use a factor of 1.8 with these

other formulas if it results more

convenient

so having seen the different temperature

scales let's move on to the instrument

used to measure it which is the

thermometer

there are different types of

thermometers depending on their

principle of operation the most commonly

used in meteorology and Aviation are the

metallic Mercury and electrical

resistance thermometers

however it is important to clarify that

besides these there are other types of

thermometers used for different purposes

such as the infrared and thermocouple

thermometers

now apart from the thermometer another

instrument used in meteorology is the

thermograph which is used to record

temperature over time using a constantly

moving paper

this instrument allows to analyze

temperature behavior and therefore

predict future changes in weather

conditions

now of course it is important that both

the thermometer and the thermograph be

located in a place where they can give a

correct reading of the actual air

temperature it is for this reason that

these instruments are installed inside a

Stevenson screen also known as

instrument shelter

this is basically a specially designed

structure that ensures a proper air

temperature measurement since it

prevents it from being affected by solar

radiation precipitation or Surface

Heating

so to achieve the best level of accuracy

in the temperature measurement this

structure is designed so that the

instruments are located at a height

between 1.2 and 2 meters above the

surface and at a distance of about 4

meters from other structures

now this is how air temperature is

measured at the surface but if what we

want is to measure the temperature at

different altitudes then radiosons

attach to weather balloons are used

which are launched from the surface up

to an altitude of approximately 65 000

feet

these devices consist of a radiosond

that contains the different measuring

instruments a radar reflector that

allows to track its position and the

balloon itself however we have to say

that to track its position more

accurately most modern models

incorporate a GPS antenna instead of

radar reflectors

so far we have seen how temperature is

measured let's now see how we can

measure heat

so since heat is a form of energy it can

be measured as such using joules which

is the standard unit of measurement of

the International System

however in some cases is more practical

to measure it in terms of the amount of

energy required to change the

temperature of a body or substance which

can be done by needs of the calorie

by definition a calorie is the amount of

energy required to raise the temperature

of one gram of water by one degree

Celsius

specifically it corresponds to the

energy required to raise the temperature

of one gram of water from 14.5 to 15.5

degrees Celsius under standard

conditions at sea level

with all this in mind we can say that

one calorie is equal to

4186 joules

now it is important to note that not all

materials and substances require the

same amount of heat to change their

temperature as this depends on their

specific heat

by definition specific heat is the

amount of heat required for the

temperature of a body or substance to

increase by one degree Celsius

to understand it better let's look at

the following example let's say we have

one kilogram of two different materials

at the same temperature in this case 15

degrees Celsius and the objective is to

increase its temperature by one degree

now

let's say that according to their

characteristics the material a needs

less heat than the material B to

increase its temperature

this way we can say that material a has

a lower specific heat than material B

now this concept of specific heat is

directly related to the heat capacity of

a material

in simple terms heat capacity is the

ability of a material to absorb a lot of

heat without changing its temperature

very much

so according to this we could say that

material a has a low heat capacity since

it changes its temperature pretty easily

with small amounts of heat while on the

other hand material B has a high heat

capacity since it is able to absorb or

release large amounts of heat without

changing its temperature too much

with this in mind we have to say that

each material or substance has a certain

specific heat which determines how

easily its temperature changes with heat

transfer

here we can see a table with the

specific heat of different substances

and materials let's look at a practical

example using this information as we can

see water has a specific heat of one

calorie per gram per degree celsius

while iron has a specific heat of 0.11

which is almost 10 times lower than

water

so according to this if we had the same

amount of water and iron at the same

temperature and we expose them to a heat

source of 1000 calories their

temperature would change differently

in the case of water since it has a high

heat capacity its temperature increases

by only one degree

while in the case of iron which has a

lower heat capacity its temperature will

increase almost 10 times more in this

case 9 degrees

so with all that we have discussed so

far it is natural to think that whenever

heat is added to a body or substance its

temperature will increase according to

its specific heat and in most cases this

is true

this heat used to increase the

temperature of a body or substance is

known as sensible heat

however there is another effect that

heat input to a body can produce and it

is a change of state

during this process despite the fact

that heat is being added the temperature

remains constant and this is because the

heat is being used to change the state

of the body or substance rather than for

increasing its temperature

this heat used to change state is known

as latent heat

latent heat is defined as the heat that

is released or absorbed by a body or

substance during a change of state while

the temperature remains constant

for example for water to change from

solid to liquid state Laden heat is

required to produce the change of state

in the same way to change from liquid to

gaseous State latent heat is also

required

now since this latent heat is not used

to change the temperature it remains

somewhat hidden inside the body or

substance until it is eventually

released when the opposite change of

state takes place

for example to change from gaseous to

liquid state the latent heat that was

absorbed during the vaporization is now

released and the same happens when the

water changes from liquid to solid state

latent heat is now released to the

environment

in this way we could summarize that

latent heat is energy that is used to

change State rather than changing

temperature and it is absorbed or

released depending on the process

involved

with all this Concepts clear let's look

at a final example where we can observe

the relationship between sensible and

latent heat

suppose we have an ice cube at a

temperature of minus 30 degrees Celsius

and we start adding heat to it so

initially the temperature of the Ice

Cube will start to increase gradually

and therefore since the heat is being

used to increase the temperature then we

say that it is sensible heat

now this will happen until the

temperature reaches 0 degrees Celsius

which is the freezing point of water

from this point on the heat absorbed by

the Ice Cube will not be used to

increase its temperature but to change

from solid to liquid state

this means that this is no longer

sensible heat it is now latent heat and

during all this process the temperature

will remain constant and zero degrees

now when the ice has completely melted

the heat will again be used to increase

the temperature of the water so again we

have sensible heat this will happen up

to a temperature of 100 degrees Celsius

which is the boiling point of water the

from this point on the incoming heat

will be used to change from liquid to

gaseous state which means that it is now

latent heat again and therefore the

temperature will remain constant at 100

degrees until all the water has

evaporated once that happens the heat

will be used again to increase the

temperature of the water vapor and

therefore it is now sensible heat again

so with this we have now understood the

basics of how heat and temperature

behave which is essential to understand

the development of most meteorological

phenomena that we will be looking at in

future videos

I hope the information presented in this

video was useful if so don't forget to

share like subscribe and leave a comment

down below it would help me a lot thanks

for watching and I see you next time

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