Transcript text: Wed Jan 1
74 CALCULUS AB
Section II Part B: No calculator is allowed for these problems.
\begin{tabular}{|c|c|c|c|c|c|c|}
\hline$t$ & 0 & 2 & 5 & 9 & 13 & 15 \\
\hline$h^{\prime}(t)$ & 0.4 & 0.5 & 0.7 & 1.0 & 1.1 & 1.3 \\
\hline
\end{tabular}
3. A tank with a rectangular base measuring 10 inches by 20 inches is being filled with water at a variable rate. The depth of the water in the tank is given by a twice-differentiable function $h$ of time, $t$, measured in minutes. The table above gives the rate of change, $h^{\prime}(t)$, of the depth of the water in the tank for selected values of $t$ over the time interval $0 \leq t \leq 15$. During this interval $h^{\prime \prime}(t)>0$. When $t=5$ minutes, the depth of the water is 6 inches.
(Note: The volume of the water in the tank is given by $V=l w h$.)
(a) Approximate the depth of the water in the tank at $t=4$ minutes using the tangent line approximation at $t=5$. Is your estimate greater than or less than the true value? Give a reason for your answer.
(b) Find the rate of change of the volume of the water in the tank at $t=2$ minutes. Indicate units of measure.
(c) Use a left Riemann sum with five subintervals indicated by the table to approximate $\int_{0}^{15} h^{\prime}(t) d t$. Using correct units, explain the meaning of $\int_{0}^{15} h^{\prime}(t) d t$ in terms of the depth of the water in the tank.
(d) Is the approximation in part (c) greater than or less than $\int_{0}^{15} h^{\prime}(t) d t$ ? Give a reason for your answer.