Temperature
Physics · तापमान · 15 facts
Temperature: measure of hotness/coldness; average KE of molecules
Three scales: Celsius (C), Fahrenheit (F), Kelvin (K)
F = (9/5)C + 32; K = C + 273.15
Water freezes at 0C=32F=273K; boils at 100C=212F=373K
Absolute zero = 0K = -273.15C; lowest possible temperature
-40 degrees is same in Celsius and Fahrenheit (-40C = -40F)
Clinical thermometer: range 35C-42C; kink prevents mercury falling back
Normal human body temperature = 37C = 98.6F
Kelvin is SI unit of temperature; no degree symbol used
Mercury thermometer: -39C to 357C; alcohol for lower temperatures
Pyrometer: measures very high temperatures (>1000C) without contact
Thermocouple: two different metals at junction measure temperature
Sun surface temperature ~6000C; core ~15 million C
Temperature of liquid nitrogen = -196C; used for cryogenic storage
Celsius scale defined: 0C = ice point, 100C = steam point at 1 atm pressure