MATHEMATICS · Single correct · A Level · Mathematics · Differentiation · Differentiation
Problem
A water tank is draining, and the volume of water remaining in the tank t minutes after drainage begins is modeled by a differentiable function V, measured in liters. At t=5, it is known that V′(5)=−3.2. Which of the following statements best interprets this value in context?
(a) During the first 5 minutes, the volume of water has decreased by approximately 3.2 liters.
(b) At 5 minutes, the volume of water is increasing at a rate of about 3.2 L/min.
(c) At 5 minutes, the volume of water is decreasing at a rate of about 3.2 L/min.
(d) It takes roughly 3.2 minutes for one liter of water to drain when t=5.