A certain truck uses $$\frac{1}{12}$$ + $${k}{v}^{2}$$ gallons of fuel per mile when its speed is v miles per hour, where k is a constant. At what speed should the truck travel so that it uses $$\frac{5}{12}$$ gallon of fuel per mile?
(1) The value of k is $$\frac{1}{10800}$$
(2) When the truck travels at 30 miles per hour, it uses $$\frac{1}{6}$$ gallon of fuel per mile.