1. Jul 16, 2013

### Anonymous119

Hello, i have one question about work,
Does work must be mechanical ?
or we can change of some energy that is not mechanical (like internal or chemical)
call work ?

2. Jul 16, 2013

### Staff: Mentor

Yes. If an energy transfer between two objects is caused by a difference in their temperatures, we call it heat, otherwise we call it work. Chemical work is an example of non-mechanical work.

3. Jul 16, 2013

### Anonymous119

Ok thanks, then i have new question,
If it says that is change of internal energy 1/3 of total work,
in total work i should count sums of every energy changes ?

4. Jul 17, 2013

### Staff: Mentor

I'm sorry, I don't understand the question. Can you re-phrase it in other words, or quote the problem or text that you're reading?

5. Jul 17, 2013

### Anonymous119

Ok, if it says that change of internal energy is part(for example 1/3) of TOTAL work executed over system(body). Does it mean that is TOTAL work indeed sums of every single work(mechanical work+internal energy change+...) ? If u understand me

Last edited: Jul 17, 2013
6. Jul 19, 2013