In Equilibrium thermodynamics by C.J Adkins he mentions an example about degrees of freedom of a thermodynamic system --
Very often for a simple system it is possible to say immediately that how many degrees of freedom it has from a knowledge of it's properties .For example , a wire subject to tension only has 2 degrees of freedom ,for it is known that it's length depends on tension and temperature only
So I don't really understand that how he concludes that the wire has only two degrees of freedom only by knowledge of the fact that it's length depends only on tension and temperature..
Because for me there are many more thermodynamic properties of this system apart from it's length...so how can we conclude it.