Stone empty of water contained in a whirlpool tub. The bathtub holds 1600 liters of water. It takes two hours to completely empty it. The volume of water contained in the bathtub is represented by the formula V(t)=1/9 (120-t)^2 , where V represents the volume in liters at time t expressed in minutes in the interval 0 t 120. Define an algebraic expression, with respect to t and h, that represents the average rate of change in the volume of water in the tub. Simplify your expression. Determines the average volume change rate between t=1s and t=2s Estimate the instantaneous rate of change in the volume of water in the bathtub at 20 mins, 40 mins and 60 mins. Determine the equation of the tangent at t = 60 mn. Sketch a graph of the curve and the tangent at t = 60 min. Check your results in d) using a graphing calculator