Questions: Liquid leaked from a damaged tank at a rate of r(t) liters per hour. The rate decreased as time passed and values of the rate at five-hour time intervals are shown in the table.
t(hr) r(t)(L / h)
0 9.5
5 8.7
10 7.9
15 7.3
20 6.6
25 6.1
Find lower and upper estimates for the total amount of liquid that leaked out.
lower estimate = liters
upper estimate = liters
Transcript text: Liquid leaked from a damaged tank at a rate of $r(t)$ liters per hour. The rate decreased as time passed and values of the rate at five-hour time intervals are shown in the table.
\begin{tabular}{|r|r|}
\hline$t(h r)$ & $r(t)(L / h)$ \\
\hline 0 & 9.5 \\
\hline 5 & 8.7 \\
\hline 10 & 7.9 \\
\hline 15 & 7.3 \\
\hline 20 & 6.6 \\
\hline 25 & 6.1 \\
\hline
\end{tabular}
Find lower and upper estimates for the total amount of liquid that leaked out.
lower estimate $=$ $\square$ liters
upper estimate $=$ $\square$ liters
Solution
Solution Steps
To estimate the total amount of liquid that leaked out, we can use the trapezoidal rule and the left and right Riemann sums. The left Riemann sum will give us a lower estimate, and the right Riemann sum will provide an upper estimate. The trapezoidal rule will give us a more accurate estimate by averaging the left and right sums.
Step 1: Calculate Lower Estimate
To find the lower estimate of the total amount of liquid that leaked out, we use the left Riemann sum. The formula is given by:
\[
\text{Lower Estimate} = \sum_{i=0}^{n-1} r(t_i) \Delta t
\]
where \( \Delta t = 5 \) hours and \( r(t_i) \) are the rates at the left endpoints of the intervals. Thus, we have: