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TRANSCRIPT
What is temperature?
• A measure of the hotness or coldness of a substance
• The average kinetic energy per molecule in a substance
Three Scales
• Fahrenheit
• Celsius
• Kelvin
Daniel Fahrenheit (1686-1736)
• First used alcohol (1709)
• Mercury much more accurate (1714)
• Used four temperature points (1724)
– Salt-ice mixture (0)
– Freezing point of water (30)
– Body (90)
– Boiling point of water (240)
• Adjusted his temperatures
Fahrenheit Scale
• Freezing point of water 32˚F
• Boiling point of water 212˚F
• Body 98.6˚F
Anders Celsius (1701-1744)
• Used just two points for his scale (1742)
– Freezing point of water
– Boiling point of water
• Performed numerous experiments to see if the freezing point and the boiling point were consistent with latitude
Celsius Scale
• Freezing point of water 0˚C
• Boiling point of water 100˚C
Lord Kelvin (1824-1907)
• Coldest temperature possible (1748)
–Absolute Zero
•0 K
•273˚C
Conversions
Convert 40
Convert 240K
Conversions
Convert 30
Conversions
Convert 75˚F to