Summary

This activity is for a Calculus class to help students visualize how to calculate volume by the disc method. Students will be given a typical volume problem and create 6 to 8 discs to approximate the shape. Then they make the actual shape and calculate the volume.

This is the companion activity to Finding Volume: Shell Method http://www.thingiverse.com/thing:1696726

Print Settings

Printer Brand:

MakerBot

                                            <p class="detail-setting printer"><strong>Printer: </strong>                     <div><p>MakerBot Replicator</p></div></p>                                                                                <p class="detail-setting rafts"><strong>Rafts: </strong>                     <div><p>Yes</p></div></p>                                                                                <p class="detail-setting supports"><strong>Supports: </strong>                     <div><p>Yes</p></div></p>                                                                                <p class="detail-setting resolution"><strong>Resolution: </strong>                     <div><p>standard</p></div></p>                                                                                <p class="detail-setting infill"><strong>Infill: </strong>                     <div><p>10%</p></div></p>

How I Designed This

To create the rotated object and the discs I first got the 2 dimensional graph using desmos.com. Then I did a printscreen to capture the graph [figure 1]. I used an online SVG converter and opened it in 123d Design. I used the polyline tool to enclose the region. Then I used polyline again to draw a line acting as the x axis that this shape would get rotated over [Figure 2]. Next I drew rectangles at each interval point with a small width [Figure 3]. Then I used the revolve tool to rotate each rectangle around the line I drew [Figures 4]. To get the full object I revolved the whole graph around the line [Figure 5]. I scaled both objects by .4 so that they would print smaller.

figure 1

figure 2

figure 3

figure 4

figure 5

Finding Volume: Disc Method