Use the kinematic equation - to solve for your reaction time, . The variable , initial velocity, is zero because you are releasing the meter stick from rest. So, the equation can be solved for time,

1. PHS101 Spring 2023: Measuring Your Reaction Time: Using Two methods

ENTER HERE THE NAME (GROUP NUMBER) YOU ARE PART OF: ___________

Every student must measure their reaction time by completing BOTH sections of this worksheet, where each part uses a different type of method.

I) SECTION ONE: “Ruler drop and catch method”

Materials: plastic or paper ruler

Introduction: Your reaction time affects your performance in many everyday activities – from driving a car to playing sports to catching something that you drop. Reaction time is the amount of time between an event and your response to it. You will need to work with one other person during this lab.

Procedure:

1. One person will hold a meter stick vertically between the thumb and index finger of the other person’s open hand. The ruler should be held so that the zero mark is between your fingers and the 1 cm mark is above it.

2. The person catching the ruler should not be touching the ruler and their catching hand should not be moving in any way. The forearm of the person waiting to catch the ruler should be resting on the edge of the table.

3. Without warning release the ruler, so that it falls between the thumb and finger of the person catching the ruler.

4. The person catching should catch the ruler as quickly as possible.

5. Record the distance the ruler has fallen through the catcher’s fingers.

6. Perform at least 12 trials. Remember to convert centimeters to meters (1 m = 100 cm). So, divide your centimeter measurements by 100 to get meters (m).

Analysis: Use the kinematic equation - to solve for your reaction time, . The variable , initial velocity, is zero because you are releasing the meter stick from rest. So, the equation can be solved for time, yielding an answer of where is the distance the meter stick fell through your grasp and .

1 In the table below, record the drop distances. Make sure you convert the centimeter reading to meters before entering the number in the table!

2. For each value in the first column, calculate using the equation above. Enter the values in the second column. Repeat this at least 12 times.

3. Calculate your average reaction time and enter this in the last line.

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II. SECTION 2: (Use a web application/game to measure reaction time again with another method. You must complete this section as well as the above section.)

1. Use a web application game (like one listed below or other you may find) that allows you to test your reaction time:

https://faculty.washington.edu/chudler/java/redgreen.html

From the web game application you choose to use, find your average reaction time the web-based “game” reports, LIST results HERE after getting at least 10 results.

Note: If you get a value that is obviously MUCH larger than others (like twice as long as the others or more), you should assume it was a “mistake” and omit it, and try again. (For example, a value 2 or three times larger than most others.)

Game reaction time 1: _________________

Game reaction time 2: _________________

Game reaction time 3: _________________

Game reaction time 4: _________________

Game reaction time 5: _________________

Game reaction time 6: _________________

Game reaction time 7: _________________

Game reaction time 8: _________________

Game reaction time 9: _________________

Game reaction time 10: _________________

Average of these game reaction times:_________________________

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Questions: (Be very descriptive and support with data/evidence when necessary.)

1. What was your average reaction time, considering both methods above:

Reaction time from SECTION 1 above:______________

Reaction time from SECTION 2 above:______________

Take the Overall average of these TWO reactions times:_____________

(this is the overall value you should share with your group members)

2. How consistent are the results above from the Section 1 (ruler drop method)? Were most of the results within a small range (like 0.05 seconds) or were there several “outliers”? Be specific with numerical ranges, do not just use words like “very” or “fairly”, etc…BE SPECIFIC.

3. How consistent are the results above from the Section 2 computer method? Were most of the results within a small range (like 0.05 seconds) or were there several “outliers”? BE SPECIFIC.

4: Did you find an overall difference in the average value using the two methods, where one method consistently gave a slightly different time value compared to the other method? List some factors or ways your body/brain/eyes react or has to process the “game” in each case that may lead to slightly different times.

You are responsible for submitting this document using the assignment upload link in this module to get credit.

AFTER your submission: you are responsible for sharing your result (the overall average result from the two methods in question 1) with your group, communicating in your group space.