In a certain experiment, liquid helium at an initial temperature of 1 K is to be further cooled by bringing it into contact with a paramagnetic salt which is initially at temperature T₀ . The heat capacity of liquid helium is expressed as C_h=a T^3 (a=128 10⁻⁴ . . J K ⁻⁴ ) and that of salt is expressed as C_s=b T⁻² (b=15 10⁻⁴ ~J . . K ) . Assume that the mixture is thermally and mechanically isolated and no work is d