Converting Between Temperature Scales (Celsius, Fahrenheit, and Kelvin)

Summary

Professor Dave's tutorial on temperature conversions covers the three main scales: Fahrenheit, Celsius, and Kelvin. He explains the context and reference points for each, and provides equations for conversions between them. The video demonstrates how to determine which location is hotter by converting temperatures and highlights the scientific importance of Kelvin as the SI unit, emphasizing its absolute nature and its relation to Celsius.

Takeaways

• 🌡️ Temperature is a significant aspect of human experience and can be a conversation starter.
• 📏 There are three commonly used temperature scales: Fahrenheit, Celsius, and Kelvin.
• 🇺🇸 Fahrenheit is primarily used in the United States and its territories.
• 🌍 The rest of the world predominantly uses Celsius for temperature measurement.
• 🔬 The scientific community often uses Kelvin for calculations as it is the SI unit for temperature.
• 🔄 Conversion between temperature units is necessary for various purposes, such as comparing temperatures or performing scientific calculations.
• ❄️ Celsius sets the freezing point of water at 0 degrees and the boiling point at 100 degrees.
• 🔥 Fahrenheit sets the freezing point of pure water at 32 degrees and the boiling point at 212 degrees.
• 🔢 The conversion rate between Fahrenheit and Celsius is 9/5 for the temperature rise, with a 32-degree offset.
• 🌡️ An example given is comparing the temperature in Los Angeles (95°F) and Rome (32°C), illustrating the conversion process.
• ⚛️ Kelvin is an absolute temperature scale where 0 K is absolute zero, the lowest possible temperature.
• 🔄 The conversion between Celsius and Kelvin is direct, with each degree Celsius equaling one Kelvin.
• 📚 The script encourages viewers to subscribe for more tutorials and support the content creator.

Q & A

What are the three commonly used temperature scales?

The three commonly used temperature scales are Fahrenheit, Celsius, and Kelvin.

In which country is Fahrenheit used as the primary temperature scale?

Fahrenheit is used primarily in the United States and a few of its territories.

What is the scientific community's preferred temperature scale for calculations?

The scientific community typically uses Kelvin for calculations as it is the SI unit for temperature.

Why might someone need to convert between Fahrenheit and Celsius?

One might need to convert between Fahrenheit and Celsius to compare temperatures between different regions, such as determining whether it was hotter in California or Italy on a given day.

How does the Celsius scale define the freezing and boiling points of water?

In the Celsius scale, the freezing point of pure water is set at 0 degrees, and the boiling point at 100 degrees.

What are the reference points for the Fahrenheit scale in terms of water's freezing and boiling points?

In the Fahrenheit scale, the freezing point of pure water is 32 degrees, and the boiling point is 212 degrees.

What is the relationship between the rate of temperature change in Fahrenheit and Celsius?

Fahrenheit temperatures climb at a rate of 9/5 that of Celsius temperatures.

What is the significance of absolute zero in the context of the Kelvin scale?

Absolute zero, which is 0 Kelvin, represents the lowest possible temperature and is the basis for the absolute temperature scale.

How is the Kelvin scale related to the Celsius scale?

The Kelvin scale is derived from the Celsius scale, with each degree Celsius being equal to 1 Kelvin.

Why is it not possible to have temperatures below zero on the Kelvin scale?

It is not possible to have temperatures below zero on the Kelvin scale because it is an absolute temperature scale, and negative values do not make sense when discussing heat energy.

How can you convert a temperature from Celsius to Kelvin?

To convert a temperature from Celsius to Kelvin, you can simply add 273.15 to the Celsius temperature.

What is the temperature in Kelvin for a day that is 95 degrees Fahrenheit in Los Angeles?

A temperature of 95 degrees Fahrenheit in Los Angeles would be approximately 308 Kelvin.

Outlines

00:00

🌡️ Temperature Conversion Basics

Professor Dave introduces the concept of temperature conversions, emphasizing the importance of understanding different temperature scales in daily life and scientific calculations. He explains that while most people are familiar with only one scale, there are three main scales: Fahrenheit, Celsius, and Kelvin. The United States primarily uses Fahrenheit, the rest of the world uses Celsius, and the scientific community often uses Kelvin for calculations. The professor outlines the reference values for each scale, highlighting the freezing and boiling points of water as the basis for Celsius and Fahrenheit. He also introduces the conversion equations between Fahrenheit and Celsius, noting the 9/5 ratio and the 32-degree difference in their zero points. The summary includes an example of comparing temperatures in Los Angeles and Rome to determine which is hotter, demonstrating the application of the conversion equations.

05:01

🔢 Understanding Kelvin and Absolute Zero

This paragraph delves into the Kelvin scale, the SI unit for temperature, which is an absolute scale with zero Kelvin representing absolute zero—the lowest possible temperature where no heat energy is available. The professor explains that negative temperatures are not possible in Kelvin because temperature measures heat energy, and absolute zero is the point where all molecular motion theoretically stops. He contrasts this with Fahrenheit and Celsius, which can have negative values. The paragraph also provides a brief explanation of how to convert Celsius to Kelvin, using the example of a hot day in Los Angeles, and mentions that such conversions are common in chemistry. The summary concludes with an invitation for viewers to subscribe to the channel for more tutorials, support the professor on Patreon, and reach out via email.

Keywords

💡Temperature Conversions

Temperature conversions involve changing a temperature value from one scale to another. The video script discusses the importance of understanding and converting between Fahrenheit, Celsius, and Kelvin scales. This concept is central to the video's theme, as it is the main subject being taught. For example, the script mentions the need to convert between Fahrenheit and Celsius to compare temperatures in different countries, such as whether it is hotter in California or Italy on a given day.

💡Fahrenheit

Fahrenheit is a temperature scale primarily used in the United States and its territories. It is defined by the freezing point of brine at 32 degrees and the boiling point of water at 212 degrees, with 180 degrees in between. The script explains that Fahrenheit is less intuitive than Celsius because it climbs at a rate of 9/5 that of Celsius. The script uses the example of a day in Los Angeles being 95 degrees Fahrenheit to illustrate temperature conversion.

💡Celsius

Celsius is a temperature scale widely used around the world, with the freezing point of pure water at 0 degrees and the boiling point at 100 degrees. The script emphasizes that Celsius divides the temperature range into 100 equal parts, or degrees. It is used for everyday temperature measurements and is the basis for the scientific Kelvin scale. The script provides the equation for converting Celsius to Fahrenheit and vice versa.

💡Kelvin

Kelvin is the scientific unit of temperature and an absolute temperature scale, where 0 Kelvin represents absolute zero, the lowest possible temperature. The script explains that Kelvin is derived from the Celsius scale, with each degree Celsius being exactly one Kelvin. Kelvin is essential for scientific calculations and is used to ensure that temperature values are always positive, which is crucial for equations involving heat energy.

💡Absolute Zero

Absolute zero is the theoretical lowest temperature where all molecular motion stops, defined as 0 Kelvin. The script mentions that absolute zero is equivalent to about -273 degrees Celsius and is a fundamental concept in the Kelvin scale. It is used to illustrate the impossibility of temperatures below zero in the Kelvin scale and the importance of an absolute reference point in scientific calculations.

💡SI Unit

The SI unit, or International System of Units, refers to the standard units of measurement used in science and industry. The script specifies that Kelvin is the SI unit for temperature, highlighting its importance in scientific calculations and its use as a universal standard for temperature measurement.

💡Freezing Point

The freezing point is the temperature at which a liquid turns into a solid. In the context of the script, the freezing points of water are different in Fahrenheit and Celsius scales. The script uses the freezing point to establish a reference for temperature conversions, noting that in Celsius, it is set at 0 degrees, while in Fahrenheit, it is at 32 degrees.

💡Boiling Point

The boiling point is the temperature at which a liquid turns into a gas. The script discusses the boiling points of water in both Fahrenheit and Celsius scales, using them as reference points for the scales. In Celsius, the boiling point is set at 100 degrees, while in Fahrenheit, it is 212 degrees.

💡Heat Energy

Heat energy is the energy transferred between systems or particles due to a temperature difference. The script explains that temperature is a measure of available heat energy and that this concept is crucial for understanding the Kelvin scale, where negative values are not possible because they would not make sense in the context of heat energy.

💡Conversion Equations

Conversion equations are mathematical formulas used to convert temperatures from one scale to another. The script provides the equations for converting between Fahrenheit and Celsius and between Celsius and Kelvin. These equations are essential tools for understanding how the different temperature scales relate to each other and are used throughout the script to demonstrate temperature conversions.

💡Public Small Talk

Public small talk refers to casual conversation in social settings. The script humorously suggests that discussing the day's temperature can be an easy way to start a conversation. This concept is used to illustrate the ubiquity and relevance of temperature in everyday life, even beyond the scientific context.

Highlights

Temperature is a significant aspect of human experience and can be a conversation starter.

Different units measure temperature, including Fahrenheit, Celsius, and Kelvin.

Fahrenheit is unique to the United States and a few US territories.

Celsius is the global standard for temperature measurement.

Kelvin is the SI unit for temperature used in scientific calculations.

The need for temperature unit conversion arises in various contexts, such as comparing climates or scientific calculations.

The reference values for Fahrenheit and Celsius are based on the freezing and boiling points of water.

Celsius scales 0 to 100 degrees between the freezing and boiling points of water.

Fahrenheit scales 32 to 212 degrees for the same points, with 180 degrees in total.

Fahrenheit temperatures increase at a rate of 9/5 times that of Celsius.

There is a 32-degree difference in the starting point between Fahrenheit and Celsius scales.

Conversion equations between Fahrenheit and Celsius are tested using the freezing and boiling points of water.

An example comparison of temperatures in Los Angeles and Rome demonstrates the conversion process.

Kelvin is derived from Celsius, with 1 degree Celsius equaling 1 Kelvin.

Kelvin is an absolute temperature scale, with zero Kelvin representing absolute zero.

Absolute zero is the lowest possible temperature and is equivalent to -273 Celsius.

Simple equations allow for the conversion between Celsius and Kelvin, which is common in chemistry.

An example of converting a temperature from Celsius to Kelvin is provided.

The tutorial concludes with a call to action for subscriptions and support on Patreon.

Transcripts

Hey it's professor Dave, let's learn how to do temperature conversions.

Temperature is a big part of the human experience. If you want to make small

talk in public, just bring up the temperature that day and you're good to

go, but just like mass, length, and time, we can use different units to measure

temperature, and we need to be able to convert between these units just as we

would with any other set of units. Most people are familiar with just one

temperature scale, which will depend on where they live in the world, but there

are three that are commonly used, and these are Fahrenheit, Celsius, and Kelvin.

Fahrenheit is used only in the United States and a handful of US territories.

The rest of the world uses Celsius. And the scientific community will typically

use Kelvin when doing calculations, as this is the SI unit for temperature.

Why would we need to convert between temperature units? Well we could convert

between Fahrenheit and Celsius to figure out whether it was hotter in California

or Italy on any given day. Or we might need to convert a temperature from one

of those scales into Kelvin in order to do scientific calculations. So let's

learn about the equations that will allow us to make these conversions.

In order to put these temperature scales into context, we must understand the

reference values that each scale uses. Both Fahrenheit and Celsius are defined

using the freezing point and boiling point of water. Celsius sets the freezing

point of pure water at zero, and the boiling point at a hundred, splitting up

the space between into 100 equal parts called degrees. Fahrenheit, a little less

intuitively, sets zero as the freezing point of brine, which is a salt water

solution. That puts the freezing point of pure water at 32 and the boiling point

at 212, splitting up the space between them into

180 degrees. So to understand how to convert between these, we must realize

that Fahrenheit climbs 180 degrees in the same space that Celsius climbs 100,

which requires that Fahrenheit temperatures climb at 9/5 the rate of

Celsius temperatures. But there is also a 32 degree discrepancy in where these

segments begin, and this also has to be accounted for. That means that these will

be the two equations we can use when converting in one direction or the other.

Let's test them by plugging in the freezing and boiling points of water to

ensure that we get valid results. And we can see that each conversion goes

precisely as we would expect. Now let's try a different example. Let's say that

on a particular day it's 95 degrees Fahrenheit in Los Angeles and 32 degrees

Celsius in Rome. Where is it hotter? Well let's take our Fahrenheit temperature,

plug it in here, and we get 35 degrees Celsius. Just to be thorough, let's

convert the 32 degrees Celsius into Fahrenheit as well, and we should get

about 90. So it looks like California is the winner in this round. As we mentioned

earlier, Kelvin is the SI unit for temperature, and it is derived from the

Celsius scale, in that one degree Celsius is precisely equal to 1 Kelvin.

But Kelvin is an absolute temperature scale, meaning zero Kelvin is absolute zero, or

the lowest temperature possible. Believe it or not, there is a lowest possible

temperature, because temperature is a measure of available heat energy, so if

there is no heat energy whatsoever, you are left with absolute zero. We are

used to below zero temperatures in Fahrenheit and Celsius if it is very

cold, but this is impossible in Kelvin, and for good reason, because if we do

calculations using certain equations and we plug in negative values or zero for

temperature, it will ruin our math, because it doesn't make sense to use

negative values when discussing heat energy. We need a temperature scale that

will always be positive so that we can demonstrate the proportional change in a

quantity due to temperature change. As it turns out, absolute zero is about

negative 273 Celsius, which means we can use these simple equations to go between

Celsius and Kelvin, which we will frequently need to do in chemistry.

So that same hot day in Los Angeles from before, measured in Kelvin would be

around 308. And now we should be able to convert between Fahrenheit, Celsius, and

Kelvin temperature scales. Let's check comprehension.

Thanks for watching, guys. Subscribe to my channel for more tutorials, support me on patreon so I can

keep making content, and as always feel free to email me:

by travelpod member