Thermodynamics

[Cejohnna12]

In my physics class, we were assigned to come up with a toy that would show case some concepts of thermodynamics. I was planning on making a toy car that will be powered by a pocket fan. (The pocket fan will be mounted on the rear end of the car so that it would push the car forward. Third law of motion). However, is this in anyway related to thermodynamics?

 

Thanks

[studiot]

The part 'Thermo' of the word should give you a clue that themodynamics is something to do with heat, and the rest of the word is about changes.

 

In fact we think of thermodynamics as being about heat and its relationship with other forms of energy so I would expect the toy to reflect this in some way.

 

I suppose you could argue that the change in bond energies in battery powering the car reflects a thermodynamic change, but search your soul and ask yourself

 

"Is this a good visible and obvious demonstration of Thermodynamics in action?"

 

The variable that appears in thermodynamics that does not generally appear in mechanics is temperature so I would expect the operation of the toy to have some connection to temperature.

[kisai]

Not really. Thermodynamics was originally conceived in the idea of transferring heat to work, with some waste heat to be dispersed. It was more of an engineering tool to study the performance of engines and cannons. Perhaps if you placed a contact thermometer upon the battery you could show how waste heat was necessarily generated, but the fan is a problem since it will quickly disperse it. Actually, a very easy way to demonstrate thermodynamics is to use rubber bands to propel an object and then note that the rubber bands are much warmer after they perform work.

Edited December 12, 2015 by kisai