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# Temperature

###### Matt Jones

###### Matt Jones

**M.Ed., George Washington University**

Dept. chair at a high school

Matt is currently the department chair at a high school in San Francisco. In his spare time, Matt enjoys spending time outdoors with his wife and two kids.

**Temperature** is the measure of the average kinetic energy of the particles in an object. **Temperature** in science is measured in Celsius or Kelvin.

Temperature, temperature is just a measure of the average kinetic energy within a substance in other words all the particles moving around in there how much kinetic energy do they have?

Some of the units we use to measure temperature or one that pretty much familiar with because it's still used in the United States is Fahrenheit, the Fahrenheit scale so 32 degrees Fahrenheit that's the point which water freezes, 212 degrees Fahrenheit that's the point at which water boils okay? Well then Fahrenheit was can in scientific units was converted to a unit that was a little bit more easy to use using zero Celsius, the Celsius scale as the point at which water freezes, 0 Celsius and then 100 Celsius as the point at which water boils. That's a useful temperature unit for biolo- Biology in biological systems since there's not much life that's below freezing or above the boiling point that pretty much can is a good range. However when you study Chemistry and Physics, now we want to look at you know the amount of energy in molecules and atoms and now we want to go with to a zero point that really gets to a zero meaning zero kinetic energy and that's where we use the unit Kelvin so zero Kelvin is what we call absolute zero it's the point at which no matter has any kinetic energy okay? And that point is -273 degrees Celsius so 0 Kelvin is the point at which no, no matter has any kinetic energy which we've got some formulas for conversions.

So we can say the converting Fahrenheit into I'm sorry Fahrenheit into Celsius we could say Celsius times 1.8 plus 32 degrees gives you a Fahrenheit unit okay? Often times you have to do that in a in a problem. If you've got a Fahrenheit unit you want to convert it into Celsius, you can subtract 32 and divide by 1.8 and that will give you units in Celsius. And then to convert from Celsius to Kelvin, we just have to add 273 degrees so our Kelvin unit equals our Celsius unit plus 273 degrees or our Celsius unit equals our Kelvin unit minus 273 degrees okay? Because absolute zero is -273 degrees okay?

Let's look at a problem, 100 degrees well we know that's hot right? 100 degree day is a hot day, what is that in Celsius? What is that in Kelvin? So we've got a 100 degrees Fahrenheit okay? To solve that I'm going to say that's going to equal a unit in Celsius times 1.8 plus 32 okay, and I'm going to subtract 32 from both sides and I get 68 equals 1.8 C okay and I divide by 1.8 and I get that 100 degrees Celsius equals 37.7 degrees Celsius okay? 37.7 degrees Celsius, how do I convert that into degrees Kelvin okay? Well I just add 273 degrees to it so 37.7 degrees Celsius plus 273 degrees is going to equal 310.7 degrees Kelvin so again pretty simple formulas we can use to convert different units of temperature and temperature again is just the average amount of kinetic energy within any substance.

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###### Matt Jones

M.Ed., George Washington University

Matt is very comfortable in front of the whiteboard and is able to make every topic easy for anyone to digest. His straightforward approach to teaching is very refreshing.

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## Pieter · 1 year, 2 months ago

This is true only for an ideal gas. The average kinetic energy of H2O molecules in liquid water it its melting point is not the same as the kinetic energy of those in the ice.