Measuring very short intervals of time is hard to do. It takes expensive equipment that we do not have. But for this activity we need a way to measure your reaction time. There is a way to do it without using a stopwatch. We can estimate reaction time by measuring the distance a ruler falls then converting distance into a very accurate estimate of the time the ruler was falling. To conduct this experiment you need a three-person team with each person playing a different role.

Role:

Pitcher: The person who drops the ruler.

Batter: The person who catches the ruler.

Coach: The person who watches the batter, gives the batter strategies to improve reaction time, and records data on a data table.

1. The batter sits in a chair positioned sideways next to a desk or table.
2. The batter's forearm lays flat on the desk with fingers extending over the edge. The wrist and palm should stay on the table to prevent downward motion of the hand. The thumb and index finger extend straight out from the edge of the table with the middle finger, ring finger, and little finger closed tightly against the index finger.
3. The coach should use a ruler to check that the batter keeps his or her thumb and index finger 2 cm apart.
4. The pitcher stands in front of the batter, holding the ruler by its 30-cm end and dangling the 0-cm end of the ruler so that it is just even with the top of the batter's thumb and index finger.
5. Without any warning, the pitcher releases the ruler and the batter tries to catch it as quickly as possible.
6. The coach checks the ruler just above the index finger to see how many centimeters it fell. The coach will use the chart to convert centimeters to seconds and record the seconds on the data table.
7. The pitcher and batter repeat this procedure three times, with the coach converting then recording each trial.
8. The coach then calculates and records the average reaction time.