13. If w'(t) is the growth rate of a child in pounds per year, in 12 or fewer simple English words, what does JA w'(t) dt represent, in the context of this problem? (Do not use the words "anti- derivative" or "definite integral.") 14. Water flows from the bottom of a storage tank at the rate of r(t) = 400 - 10t gallons per minute, where 0