## The Hand Squeeze

Let's conduct an experiment. We will pass a "hand squeeze" around a circle and measure the amount of time that it takes for the hand squeeze to pass around the circle.

Collect the Data Start with two students at the front of the room. (You're eventually going to need enough space for everyone in the class to get in a circle) Have the two students hold hands. When the timekeeper says "now" the first person should squeeze the hand of the second person who then squeezes the other hand of the first person. The last person will say "now" when she feels the hand squeeze come back to her.Record that data in the table below. Now add two more students to the circle and repeat the process, passing the hand squeeze around the circle. Record that time and repeat the process with two more students.

Continue the experiment, recording the time each time until everyone has joined the circle. Have everyone try to pass the squeeze as quickly as they feel it, maintaining the same rate of speed. If someone messes up, it's okay to disregard that time and repeat the experiment.

Organize the Data

Number of Students Number of Seconds
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30

Graph the Data

Make a graph of the data by plotting the above points, letting the x axis represent the number of students and the y axis represent the number of seconds.

Analyze the Data

1. Should we connect the points to make a solid graph? Why or why not?

2. Are the points scattered all around the plane or do the points tend to be a certain shape?

3. Make a prediction: Based upon the data collected, how many seconds would it take to pass the hand squeeze around a circle of 100 people? How many minutes?
Thought Question

Imagine students lined up from your city or town to Mexico City. How long would it take to pass the hand squeeze all the way there? You can find the distance at this site.

Optional: Use Technology

Use a spread sheet to record and graph the data.