Category Archives: Physics Unit 11: Thermodynamics

Converting F to C to K

Warm Up:  {From memory} Using the formulas you learned in the lesson “3 Temperature Scales”, convert room temperature (72 F) to Celsius and to Kelvin. If you don’t remember the formula, draw a thermometer showing F and C degrees for the freezing point and boiling points of water, then compare these ranges to get the conversion factor.

Homework:  Complete this worksheet  temperature_conversion_wkst

Some important temperatures:

1] The coldest day in my life…..

I was living in Chicago and one January the temperature was  -24F that’s right!  24 degrees below zero!  Brrrrrr…………
Convert this to Celcius and to Kelvin.

2] What is Walt Disney’s body temperature?
(hint: Liquid Nitrogen boils at 77K, convert to Fahrenheit)

3] Mercury freezes at- 38.8 C. Convert to Fahrenheit.
At what temperature are Celsius and Fahrenheit degrees equal? (hint: solve the conversion formula for F/C = 1)

 

The Second Law

The Second Law of Thermodynamics:  Entropy
Any spontaneous process increases the DISORDER of the universe!
We call this ENTROPY.

Warm up: Individual work. In your notebook, describe a example in your own world where you see evidence of the trend towards disorder.

Entropy – The Good Stuff

Formula for entropy: S

S = Q / T

reference: Thermodynamic efficiency

Next lesson: car engines and the Otto cycle