in heat and thermodynamics we use different units of temperature to measure the temperature or the temperature are expressed in different units the most common units are degree celsius degree fahrenheit and kelvin in the most part in the united states mostly we measure the the temperature in fahrenheit if you go back to asia it is very common to use the temperature in celsius and in scientific world most of the time we use the units in kelvin so it is necessary to know how to convert or how to change the units from celsius to fahrenheit or celsius to kelvin or kelvin 2 fahrenheit so i have made a list here so he if you have to change from celsius to fahrenheit this is the relation here okay tf is equal to 9 over 5 tc plus 32 32 and again from this equation you can easily calculate or solve for tc so these equations are basically the same if you know an equation to go from celsius to fahrenheit then you can use the same equation to go from far and height to celsius so you have to remember only one and from calculating celsius to kelvin it's pretty straightforward so you have to simply add 273 to the degree celsius to get to the the kelvin okay and also i would like to mention here the fahrenheit and celsius are exposed in degree but the kelvin is simply expressed in numbers okay so we call the degree fahrenheit degree celsius but we do not call degree kelvin we simply call kelvin and here is the relationship between the fahrenheit and kelvin and kelvin 2 for an eye if you remember this equation only then the rest you can divide by yourself because it is simple to use from kelvin to celsius ttk is equal to tc plus 273 and once you remember this equation that you can simply plug back in if you can change the tc and plug in here then there will be a relation between the fahrenheit and kelvin okay but um i have just listed all the relations here so that it is easier for you but i recommend if you want to memorize so just remember this equation and the rest you can write by yourself okay at 40 degree at 40 degree both celsius both celsius and fahrenheit are exactly the same and you can easily solve this one easily so what you can do so you can just plug in if you solve for uh using this equation you can easily solve for like what temperature the celsius and fahrenheit are exactly the same and i will and just to demonstrate that or just to mathematically show that at a minus 50 degree both celsius and fahrenheit are exactly the same as in the my other videos the or the two other things that you need to remember is water boils at 100 degrees celsius and if you remember if you want to memorize or if you want to remember in degree fahrenheit it is exactly equal to 212 degree fahrenheit and in kelvin this is 373 kelvin so you just have to add 273 to this similarly water freezes at 0 degree celsius and which is equivalent to 32 degree fahrenheit and in kelvin this is equal to 273 kelvin absolute zero temperature is zero kelvin zero kelvin which is equal to minus 273 celsius and in for a high that is equal to minus 459.7 degree fahrenheit when i say absolute zero what does that mean the temperature cannot go below zero kelvin or the kelvin cannot be in negative numbers okay so it can it is impossible for any material to be negative kelvin okay or it cannot be a smaller than minus 273 degree celsius so the zero kelvin is absolute zero temperature that's the reason we call absolute zero it cannot be a smaller than that okay any temperature cannot be a smaller than the absolute zero temperature it has to be always positive kelvin temperature so in order to change from one unit to another i will demonstrate one example here the sun's average temperature is surface average temperature is 5500 degree celsius now if i ask you to change this temperature to foreign height and kelvin how are you going to do that so we have to change from celsius to further higher so we're going to use this equation which is listed here foreign height so we are given the degree celsius and how much it is 5500 so just going to plug in 5500 and this is a number here you just have to solve it and get it to 9935 degree fahrenheit okay and the other thing is how do you change this one to kelvin so again remember if you if it is given in celsius then you simply have to add 273 to get to the kelvin so this is it the one last thing i'll just like mention here quickly as i mentioned here at what temperature the celsius and kelvin are equal so the way you can calculate is so if you plug in let's say here tf minus 14 as i mentioned so 9 over 5 times minus 40 plus 32 so if you do the math what you get here 5 times minus 40 is minus 8 so 9 times -8 plus 32 is a minus 72 plus 32 if you do the math you'll get minus 40. so you see now so i'm here i'm just plugging this degree celsius to minus 40 and solve it you get the minus 40. that means at minus 40 degree celsius and minus 40 degrees fahrenheit referred exactly to the same temperature okay so this is it from this video and it is a pretty straightforward mostly the algebra and just remember few equation here so this equation and this equation if you remember these two equation then you can derive the other equations okay so this is it again if you have any questions write down your questions in the comment section below thank you very much please do not forget to like share and subscribe the channel thank you