2002AJ....123..382V

Interstellar gas comes with empirical physical relations governing mean parameters such as the gas density n, diameter D, magnetic field B, and gas line width σ, with the forms <n>~D^c, <B>~<D>^p, <B>~<n>^k, <σ>~<D>^q, and p=ck. Using these results, I derive simple formulae for the energy components in turbulent young stellar objects of Classes 0 and I as a function of clump size D (D<0.5 pc) from empirical fits to observations. Here I find the relative importance of the energy components in molecular clumps, each one of the form <E>~D^x, with x ranging from 0 to 3. Magnetic and gravitational energies are more important for small D (<0.1 pc), while for large D (>0.1 pc) turbulent and gravitational energies become dominant (x=2). In addition, the expected relationship between turbulent width and magnetic field, <σ>~<B>^q/p^, is not steep, and the observational data to date bear this out. Damping scenarios, magnetic field shapes, and ambipolar diffusion relevant to observations are discussed.