Temperature

Now the words temperature and heat are often used interchangeably with one another, but they're not the same thing. They represent different aspects of thermal energy. Now, thermal energy itself is the sum of all kinetic and potential energies of all atoms in an object. Now, when we say kinetic energy, we know that kinetic energy is the energy of motion. Okay, so the movement of molecules, the movement of atoms, potential energy is just the energy of position. Where those molecules are related. Are they 100 ft off the ground? Are they 10 ft off the ground? Where exactly are they located? Now? Temperature, heat again are used interchangeably with one another, but they're not the same thing. Temperature itself is the average kinetic energy of an object. That is a measurement of thermal energy. Remember that temperature itself is an intensive property. It is the inside or innate properties of a substance that is independent on the amount of that substance. For example, if we have a cup of water that's 100 degrees Celsius versus a gallon of water, that's 100 degrees Celsius. The amount of water is different, but the temperature is the same because the temperatures the waters are are at at the moment, doesn't matter how much of the water we have. Okay, so temperature is an intensive property. Heat on the other hand, is not heat is the flow Of thermal energy from the object at a higher temperature to an object at a lower temperature. Okay, so it's normal for heat to move from a hotter object to a colder object. If you have a hotter object next to a colder object, eventually all the heat from the hotter object moves towards the colder one. So to heat it up, heat itself is based on the amount of the substance present. So it would represent an extensive property. Now, knowing the difference between temperature and heat is critical for the example, that's left right below it. If we take a look at this example, question it says from the image provided below, determine which part of the cubes represent temperature and which part represents heat. Alright, so we have two cubes here and we can see that the cube on the left has those little red balls that seem to be bouncing everywhere. They're highly energetic. That happens because the overall temperature in this cube is higher. So we say that this cube has a higher temperature. Then if we look on the other side we see that they are kind of like stuck in place not moving at the same speed as before. That's because there are a lower temperature. And remember we just said that heat goes from a higher temperature to a lower temperature object. That is explained by these wavy lines. So here we see that heat is leaving the left Cuban going to the right cube. So these wavy lines represent heat. So that's how you need to understand temperature is an actual measurement, 100 20 98 F. Uh These are actual numbers. Heat is just a flow of of of thermal energy from a hotter object to a colder object, although they're used interchangeably. Sometimes they are not the same thing now that we've talked about the difference between intensive when it comes to temperature and extensive when it comes to heat. Let's move on to our next practice question.

hey everyone. So here in this example question it says the image provided below determine which part of the cubes represent temperature and which part represents heat. So remember heat itself just represents the flow of thermal energy from an object that's hotter to an object that's colder. If we take a look here, we have these two cubes and we can see that we have a set of wavy lines between them. These set of wavy lines themselves represent our heat. Temperature itself is a result of the movement of molecules within a given structure. So if we take a look here, we can see that in the first cube, let's call it Cube one. We can see that we have these little balls that are moving around and in the second cube, cube two we have the same balls but they're not moving as vigorously. We're gonna say here temperature is really just the movement in each cube. So you could say that temperature is represented by the molecules moving in this cube as well as in this cube. Remember we said that heat is the flow of energy from a hotter object to a colder object. The objects in the first cube, we can see them moving more vigorously more more actively. Therefore they would generate higher temperature. So we'd say that Cube one would have a higher temperature And the balls in the 2nd Cube are moving slower. So they have a lower temperature. This reinforces the idea that heat which we said are these wavy lines would go from cuba one to cube to they're going from a higher temperature to a lower temperature. So keep this in mind when learning the distinction between heat and temperature.

Yeah. Now temperature can be measured in units off Celsius, Fahrenheit and Calvin. And when it comes to these temperature units, we can convert between them in order to convert between them. We just have to utilize certain formulas. Now, here we have purple boxes, and when we have these purple boxes, that means that that's a term or formula you have to memorize. Okay, you have to commit it to memory because oftentimes it's not given to you on an exam or quiz. Now the first one connects Calvin two degrees Celsius, and it's that Calvin equals degree Celsius plus to 73.15. Oftentimes, professors will drop the 0.15 part. But to be as accurate as possible, it's important that you use the whole number so to 73. from this equation, we can see that Kelvin directly connects two degrees Celsius and we could go between them. The next equation connects degrees Fahrenheit two degrees Celsius, and the equation is degrees Fahrenheit equals 1. times degree Celsius plus 32. So this formula here shows us that degrees Celsius is connected F. So from these three units, we can see that Celsius is in the middle, so Celsius acts as the bridge that connects Kelvin F. So just remember, when it comes to temperature, we have three units that we can use. And when it comes to changing between them, these are the two formulas you need to commit to memory Anytime you see a purple box, remember, that means you're gonna have to memorize either that term, that definition or, in this case, off formula.

Let's take a look at the following example question here. It says one of the hottest recorded days in the country was 128 F in Lake Havasu City, Arizona. If the melting point of phosphorus is 44 15 degrees Celsius, what it exists as a solid or liquid on this extremely hot day? Alright, so we see that in the question. We're dealing with units of Fahrenheit and Celsius from the equations up above. We know what's the second one we're gonna have to use in some way. So we have degrees Fahrenheit equals 1.8 times degrees Celsius plus 32. They're giving me the temperature in Lake Havasu in Fahrenheit by me. I need to compare it to this melting point of phosphorus, which is in Celsius. If the temperature I find is equal to or greater than 44. degrees Celsius, that means that phosphorus will melt and it will be in its liquid. For if the temperature on this extremely hot day is not at least 44.15 degrees Celsius, then it won't be hot enough, and phosphorus will not melt and remain a solid so I'm gonna plug in what I have referred. Height, which is 1 28 and this is 1.8 degrees Celsius plus 32 subtract 32 from both sides. So when we do that, we get 96 equals 1.8 times degree Celsius. Divide both sides now by 1.8, and now we'll have the temperature in Lake Havasu in degrees Celsius, so our degrees Celsius here equals 53.3. Now we needed the temperature to would be at least 44.15 degrees Celsius for phosphorus to mount. This answer is much greater than it. So yes, it's hot enough for phosphorus to mount. Therefore, it will exist in its liquid form. Now that we've seen this example on how to relate Fahrenheit two degrees Celsius, move onto the next video and let's take a look at the practice question