
Activity Source:
Incorporated Research Institutions in Seismology, 2005. Adapted with permission.
Materials:
- 1 - One foot piece of 2x4 scrap wood
- 1 - 4"x36" Sanding Belt, 50 Grit
- 1 - 1/3 Sheet of Sandpaper, 60 Grit
- 2 - Screw Eye 12x1-3/16
- 1 - Bag of Rubber bands, varying size
- 16 in of Duct Tape
- 2 - Cloth measuring tapes with both English and metric markings
- 1 - Manila Folder
- Saw
- Needle Nose Pliers
- Scissors
- Glue (White or Contact Cement)
- Pencil
Procedure:
- Using the tape measure and pencil, divide the one-foot length of 2" x 4" into two 4" blocks.
- Using the saw cut along your markings to create two 4" x 4" blocks
- Trace one of the blocks on the back of the sandpaper & use the scissors to cut out squares
- Glue the sandpaper square to Block A
- Screw one 12x1-3/16 screw eye into a cut end of block A
- Screw one 12x1-3/16 screw eye into Block B
- Using the needle nose pliers, carefully bend the screw eye on Block A opened just enough to allow a rubber band to fit through.
- Using scissors cut the sanding belt so it is no longer a connected loop
- Using pliers remove the metal ends from one of the measuring tapes.
- Using scissors cut the measuring tape without the metal ends up the middle lengthwise, being careful to leave the cm markings intact.
- Discard the half of the split measuring tape marked in English.
- Cut four strips out of the manila folder; two that are 3cm wide and 15cm long, and two that are 3cm wide and 23cm long.
- Assemble the strips of manila folder with tape as shown if Figure 3 and tape to the top of Block A.
Setup for Use In the Lab
- Using duct tape, secure one end of the sanding belt to the lab table.
- Stretch the sanding belt out tightly and tape the second end to the lab table so that there are no waves in the sanding belt.
- On the side of the sanding belt nearest you tape down the uncut measuring tape with the metric side up in the same fashion as the sanding belt.
- Place block C on edge, on the right end of the sanding belt so that the screw eye is positioned in the center of the sanding belt.
- Using a long piece of duct tape, tape block C down to the tabletop for added support.
- Thread the split measuring tape through the screw eye and pull it to the far left end of the sanding belt.
- Fold 5 cm of the end of the split measuring tape back on top of itself with a rubber band in the loop. Use duct tape to secure the loop so that the rubber band is attached to the end of the measuring tape.
- Hook the rubber band into one of the screw eyes of block B. (*Note - If Block does not stick-slip you may need to daisy chain several rubber bands together)


Student Worksheet (20.5 KB)
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