- #1

- 139

- 16

## Summary:

- I don't understand what "net work done on the system" means in the context of the first law of thermodynamics. I am unable to understand its physical significance and why it's given in the mathematical expression of the First law

The first law of thermodynamics states that the change in the internal energy of a system equals the net heat transfer into the system minus the net work done by the system. In equation form, the first law of thermodynamics is ΔU = Q − W.

in the mathematical expression of the first law of thermodynamics, I do not understand the significance of W or the net work done on the system. shouldn't simply be ΔU = Q, if Q is the net heat transfer into the system.

Clearly I am missing something very important hear but all the sources that I have referred to so far just mention the above expression and don't exactly explain W so is this something so obvious that isn't worth explicitly explaining?

in the mathematical expression of the first law of thermodynamics, I do not understand the significance of W or the net work done on the system. shouldn't simply be ΔU = Q, if Q is the net heat transfer into the system.

Clearly I am missing something very important hear but all the sources that I have referred to so far just mention the above expression and don't exactly explain W so is this something so obvious that isn't worth explicitly explaining?