Question

What is an example of the first law of thermodynamics?

Answer 1

Consider an ideal gas in a closed vessel placed with one movable piston.

Then as you heat the gas, the gas expands and thus displaces the piston performing work.

From the first law, this should be given by,

`delQ = delU + delW`

Where `delQ` is the heat you transfer, `delW` is the work done (all of them being infinitesimals) and finally the remaining part is equal to change in internal energy `delU`.