- WELCOME TO A VIDEO TUTORIAL GIVING AN OVERVIEW
OF TEMPERATURE AND THE VARIOUS UNITS
WE USE TO DESCRIBE TEMPERATURE.
LET'S BEGIN.
SO, THE DEFINITION OF TEMPERATURE
IS THAT IT'S A MEASURE OF HOTNESS
OR COLDNESS OF AN OBJECT.
THE ORIGINAL TEMPERATURE UNITS ARE NAMED AFTER A GENTLEMAN
BY THE NAME OF FAHRENHEIT.
AND THIS WAS--
THIS TEMPERATURE SCALE IS HUNDREDS OF YEARS OLD.
AND FAHRENHEIT WAS TRYING TO PURSUE THE RANGE
OF TEMPERATURES POSSIBLE.
AND HE WAS ABLE TO GO BELOW THE FREEZING POINT OF WATER.
AND SO, THAT'S WHY THE FREEZING POINT OF WATER ENDS UP BEING 32.
OUR BODY TEMPERATURE WE'RE ALL AWARE OF AND THEN
THE BOILING POINT OF WATER.
THIS TEMPERATURE SCALE SYSTEM WAS EVENTUALLY,
IN THE SCIENTIFIC COMMUNITY,
REPLACED WITH CELSIUS.
AND SO, CELSIUS FOCUSES
ON THE PHYSICAL PROPERTIES OF WATER.
SO, CELSIUS DEFINES ZERO AS THE FREEZING POINT OF WATER
AND THE BOILING OF WATER AS A HUNDRED DEGREES.
SO, IF WE COMPARE THESE TWO UNIT SYSTEMS,
WE CAN SEE THAT THERE'S A HUNDRED
AND EIGHTY DEGREES FAHRENHEIT BETWEEN THE FREEZING POINT
OF WATER AND THE BOILING POINT OF WATER.
IF WE COMPARE THAT TO CELSIUS,
WE SEE THAT THERE'S ONLY A HUNDRED DEGREES DIFFERENCE.
EVENTUALLY, WE ALSO DEVELOPED THE KELVIN SYSTEM
AND WE DON'T USE THE DEGREE SYMBOL HERE BUT THE IDEA
OF THE KELVIN SYSTEM IS THAT WE HAVE PUT THE ABSOLUTE ZERO
AS THE LOWEST POSSIBLE TEMPERATURE POSSIBLE AS ZERO.
AND NOTICE BY DOING THAT, ALL TEMPERATURES ARE POSITIVE.
AND SO, THAT'S A VERY SIGNIFICANT FEATURE
OF THE KELVIN SCALE.
SO, WHEN WE'RE WORKING WITH GAS LAWS,
GAS LAWS ONLY WORK IN KELVIN AND PART OF THAT REASON
IS BECAUSE WE NEED TO ALWAYS HAVE THE POSITIVE VALUES.
HOWEVER, THE RELATIONSHIP BETWEEN THE CELSIUS SCALE
AND THE KELVIN SCALE IS THAT THE UNITS ARE THE SAME SIZE.
IT'S ALSO A HUNDRED KELVIN
BETWEEN THE FREEZING POINT OF WATER,
WELL, I DON'T WANT THAT TO BE A DECIMAL,
AND THE BOILING POINT OF WATER,
STILL A HUNDRED DEGREES.
SO, HERE, WE CAN SEE THAT THE UNITS ARE THE SAME SIZE.
ALL RIGHTY.
SO, IN CONVERTING BETWEEN FAHRENHEIT,
CELSIUS, OR KELVIN,
THERE ARE TWO THINGS THAT WE HAVE TO CONSIDER.
FIRST IS WE NEED TO CONSIDER THE SIZE OF THE UNITS
BECAUSE WE CAN SEE THAT BETWEEN FAHRENHEIT
AND CELSIUS OR KELVIN,
THE UNITS ARE A DIFFERENT SIZE.
SO, OUR CONVERSION HAS TO ALLOW FOR THAT DIFFERENCE.
AND THEN NOTICE THAT THE ZEROES, RIGHT, SO,
THE ZERO FOR FAHRENHEIT SOMEWHERE DOWN HERE,
THEN, WE HAVE THE FREEZING POINT OF WATER AND ABSOLUTE ZERO.
SO, WE HAVE TO MAKE ALLOWANCES FOR THE LOCATION OF THE ZERO,
ZERO TEMPERATURE. ALL RIGHTY.
SO, CELSIUS TENDS TO BE THE HUB.
I'VE PUT IT IN THE MIDDLE ON PURPOSE
SO WE CAN HAVE A FORMULA THAT ONCE WE KNOW CELSIUS,
WE CAN CONVERT TO FAHRENHEIT OR FROM CELSIUS,
WE CAN EASILY CONVERT TO KELVIN.
AND HERE ARE THE TWO FORMULAS TO SHOW HOW THESE FORMULAS WORK,
NOTICE THIS NINE FIFTHS.
WHERE DOES THIS COME FROM?
THIS HAS TO DO WITH THE SIZE OF THE UNITS, RIGHT?
WHAT IF WE TAKE A HUNDRED AND EIGHTY DIVIDED BY A HUNDRED,
GUESS WHAT THAT REDUCES TO, NINE FIFTH OR 1.8.
SO, THIS FIRST TERM
IN OUR CALCULATION IS GOING TO ADJUST FOR THE DIFFERENT SIZE
OF UNITS BETWEEN CELSIUS AND FAHRENHEIT.
AND THEN, HERE WE SEE THE DIFFERENCE IN THE ZERO
SO THE + 32 IS HOW WE ADJUST FOR THE DIFFERENCES IN THE ZERO.
WHEN WE ARE GOING FROM CELSIUS TO KELVIN,
NOTICE THAT BECAUSE WE HAVE THE SAME SIZE UNITS,
WE DON'T HAVE TO WORRY ABOUT MAKING AN ADJUSTMENT.
AND THEN WE SIMPLY ALLOW FOR THE DIFFERENCES
AND THE LOCATION OF ZERO ON THE SCALE.
SO, LET'S DO ONE SET OF CALCULATIONS
TO ACTUALLY PRACTICE USING THE FORMULAS
THAT WE'VE DISCUSSED.
SO, NOW, WE UNDERSTAND WHERE THESE FORMULAS COME FROM,
LET'S PRACTICE USING THEM.
SO, THE HOTTEST TEMPERATURE
EVER RECORDED IN THE UNITED STATES WAS 56.7 DEGREES C
IN DEATH VALLEY, CALIFORNIA.
LET'S CONVERT THIS TEMPERATURE INTO DEGREES C AND-- OH, OOPS.
WE ALREADY HAVE IT IN DEGREES C. SO,
LET'S GO FOR DEGREES FAHRENHEIT AND KELVIN, RIGHT?
SO FOR DEGREES FAHRENHEIT,
IT'LL BE THE NINE FIFTHS, 56.7 + 32, SO,
WE PUT THESE VALUES INTO OUR CALCULATOR AND WE GET--
OH, MY GOODNESS, WE WOULD GET A HUNDRED
AND THIRTY-FOUR DEGREES FAHRENHEIT. WOW.
IT'S AN AMAZINGLY HOT DAY. ALL RIGHT.
AND THEN IF WE WANTED TO GO TO KELVIN, RIGHT,
THAT WOULD JUST SIMPLY BE 56.7 + 273.2, SO,
PUNCH THAT INTO OUR CALCULATOR,
AND IT WOULD BE 329.9 DEGREES KELVIN.
SO, IN THIS CASE, THE--
WITH THE 32 HERE AND ONES,
WE'LL LEAVE THE RESULT THERE
AND HERE ARE UNCERTAINTIES IN THE TENTHS
SO WE CAN LEAVE OUR RESULT INTO THE TENTHS PLACE.
SO, THAT CONCLUDES A BRIEF OVERVIEW OF TEMPERATURE SCALES
AND HOW TO CONVERT BETWEEN TEMPERATURES.
SO, GO AHEAD AND PRACTICE A FEW PROBLEMS
SO YOU FEEL COMFORTABLE WITH THESE CALCULATIONS.