The speed of a particle in a test laboratory was noted every second for 3 seconds. The results are shown in the following table. Use the left endpoints and then the right endpoints to estimate the total distance the particle moved in the first three seconds. \begin{tabular}{c|cccc} $\mathbf{t}(\mathbf{s e c})$ & 0 & 1 & 2 & 3 \\ \hline $\mathbf{v}(\mathrm{ft} / \mathrm{sec})$ & 11 & 5.5 & 5 & 3.5 \end{tabular} The estimate of the total distance the particle moved in the first three seconds using left endpoints is $21.5 \mathrm{ft}$. The estimate of the total distance the particle moved in the first three seconds using right endpoints is $\square \mathrm{ft}$.

Step 1 ：The question is asking for the total distance the particle moved in the first three seconds using right endpoints. The right endpoints in this case are the velocities at t=1, t=2, and t=3.

Step 2 ：To find the total distance, we need to sum up the product of each velocity and the time interval. Since the time interval is 1 second for each, the total distance is simply the sum of the velocities at the right endpoints.

Step 3 ：The velocities at the right endpoints are 5.5 ft/sec, 5 ft/sec, and 3.5 ft/sec.

Step 4 ：Adding these velocities together gives a total distance of \(5.5 + 5 + 3.5 = 14.0\) ft.

Step 5 ：Final Answer: The estimate of the total distance the particle moved in the first three seconds using right endpoints is \(\boxed{14.0 \, \text{ft}}\).