Second law of Thermodynamics

—> heat will always flow from a hotter body to a cooler body and entropy will always increase with it

What is meant by the term entropy?

• is the measure of a systems thermal energy per unit temperature that’s unavailable for doing work

Describe what is happening to the entropy of the universe?

• it’s increasing

How does this relate to reversible and irreversible processes?

• entropy for system -> is 0 -> is a reversible process -> no change in entropy
• any value over 0 -> is a reversible process -> gains entropy