HandsOn 3 - Creating a Rope Coastline

In order to study coastlines further, create a sample coastline using the following instructions. You will need for this activity

• a rope, such as a clothesline, about 30 meters long,
• a single die, and
• a coin.

The activity takes place with the class in a wide hall, entrance hall, or outdoors. Select one class member to roll the die and another to flip the coin.

1. Two class members, Student #1 and Student #2, stand about 20 feet apart as shown in Figure . Student #1 holds the end of the rope. Student #2 pulls the rope into a line, keeping the unused portion of the rope coiled at his or her feet.


2. Select a direction perpendicular to the rope to be the positive direction. The opposite direction will be the negative direction.


3. Student #3 grasps the rope approximately in the middle.


4. Flip the coin. Heads or tails determines the direction the person in the middle will move in Step 5 below.


5. Roll the die. The person in the middle of the rope takes a number of "baby steps'' (steps that touch heel to toe) perpendicular to the rope. The number of steps is equal to the number on the die: from one to six. The direction of these steps is determined by the outcome (heads or tails) of the coin flip performed in step 4. Student #2 lets the rope slip out to provide the extra length as needed.


6. Now Students #4 and #5 take up a position in the middle of each straight segment.

Figure 2.4: The initial steps of creating a rubber band or rope coastline as described in HandsOn 1 and 2.


7. Repeat Steps 4 through 6 for Student #4, who takes the number of baby steps indicated on the die in a direction perpendicular to the rope indicated by the coin flip. Do the same for Student #5.


8. Continue this process, randomly deflecting the midpoint perpendicular to each straight segment, until you run out of either rope or students.


9. Take a photograph of the resulting "coastline."