Difference Between Temperature and Heat
Summary
TLDRThis 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
🔍 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.
🌡️ 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.
🌡️➕ 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.
🔥 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.
Mindmap
Keywords
💡Temperature
💡Heat
💡Internal Energy
💡Kinetic Energy
💡Thermal Energy
💡Thermodynamics
💡Conduction
💡Thermometer
💡Specific Heat
💡Heat Capacity
💡Latent Heat
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
[Music]
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
[Music]
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