Thermodynamics Laws

Thermodynamics Laws

First Law of Thermodynamics

“When heat flows to or from a system, the system gains or loses an amount of energy equal to the amount of heat transferred.”

WQU

First Law of Thermodynamics

If you do work on the pump by pressing down on the piston, you compress the air inside.

Chinooks, which are warm, dry winds, occur when high altitude air descends and is adiabatically warmed.

First Law of Thermodynamics

The temperature of a parcel of dry air that expands adiabatically decreases by about 10

0 C for each km of elevation.

Second Law of Thermodynamics

“Heat of itself never flows from a cold object to a hot object.”

“In natural processes, high-quality energy tends to transform into lower-quality energy – order tends toward disorder.”

“It is impossible for any system to undergo a process in which it absorbs heat from a reservoir at a single temperature and converts the heat completely into mechanical work, with the system ending in the same state in which it began.”

“ It is impossible for any process to have as its sole result the transfer of heat from a cooler to a hotter body.”

Entropy“A measure

of disorder.”

Heat Engine

“ A heat engine is any device that changes internal energy into mechanical work.”

When heat in a heat engine flows from the high-temperature reservoir to the low-temperature sink, part of the heat can be turned into work. (If work is put into a heat engine, the flow of heat may be from the low-temperature sink to the high-temperature reservoir, as in a refrigerator or air conditioner.)

Internal Combustion Engine

Refrigerators