Rular Drop Lab   1st lab      Name____________________________________

In today’s lab you will create a hypothesis, design an experiment to test it, conduct the experiment, summarize the data, and come to a conclusion about the acceptability of the hypothesis. Working in groups of four, you are to develop a hypothesis relating to the topic of neuromuscular reaction time. This is easily measured in the lab by determining how quickly a person can catch a falling meter stick. The distance the meter stick drops before being caught can be converted to time and is a measure of the person’s reaction time.

Procedure

1. Have one member of your group (the subject) sit with both feet on the floor. This individual holds the thumb and forefinger of one hand apart, as if to grasp something.

2. A second member of the group (the experimenter) then holds the meter at the top end so that the bottom is just above the subject’s thumb and forefinger. The bottom is the end with the low numbers.

3. The experimenter announces that the meter stick will be dropped within the next ten (10) seconds. The meter stick is dropped without any further warning.

4. The subject watches the meter stick and attempts to catch it between thumb and finger when it is dropped.

5. Measure the distance from the bottom of the meter stick to the subject’s thumb and finger, in centimeters, and record this.

6. After a few practice drops, record the distance for ten (10) drops of the meter stick in table 1.

7. Calculate the average distance for the ten drops and convert this distance to a time in seconds using table 2.

8. Repeat this procedure for all four members of your group.

Some trials may result in times greatly different from the others. Should these be included in computing the average distance (and time)? Is one set of ten (10) measurements enough to determine a person’s reaction time?

 

 

 Table 1

Drop #

 1st drop (control)

2nd Drop (Experiment)

Drop 1

 

 

Drop 2

 

 

Drop 3

 

 

Drop 4

 

 

Drop 5

 

 

Drop 6

 

 

Drop 7

 

 

Drop 8

 

 

Drop 9

 

 

Drop 10

 

 

Average Distance (cm)

 

 

Reaction Time (sec) (Table 2)

 

 

Hypothesis:

 

 

 

 

Conclusion:

 

 

 

 

 

 

Table 2. Fall in centimeters versus time.

Fall Distance (cm)

Fall Time (sec)

0

0.000

5

0.100

10

0.142

15

0.174

20

0.201

25

0.225

30

0.246

35

0.266

40

0.284

45

0.301

50

0.318

55

0.333

60

0.348

65

0.362

70

0.376

75

0.389

80

0.402

85

0.414

90

0.426

95

0.438

100

0.449

 

 

 

Name:_______________________