Hands On Lab: Personal Reaction Time
Make sure you answer the questions and write up your lab report using correct procedures
outlined in the Lab Report Format Guide. It will be graded using the Lab Report Rubric.
Completed Lab Reports should be submitted to the dropbox entitled HOL: Reaction
Time. You can submit this lab in a powerpoint format or you can make a video showing
yourself completing the lab activity. If you choose to make a video, I will tell you where to
upload the video. You will not have to submit a written report if you make the video.
You can access this dropbox by clicking on the DROPBOX link on the above navigation bar.
Purpose -To investigate the speed at which objects fall and to determine your reaction time
using the acceleration due to gravity
Equipment - Table edge, metric ruler
Procedure
Experiment Variable - Your Reaction Time
1. Place your RIGHT hand on the edge of a table with the fingers and thumb sticking
out over the edge.
2. Open your fingers so they are 10 cm away from your thumb.
3. Have a partner hold a ruler even with the top of your fingers and thumb. The zero
mark on the ruler should be closest to the floor.
NO WARNING OR CLUES
4. As fast as possible, catch the ruler when your partner lets it drop.
5. Repeat four times and record the number showing above your finger and thumb.
6. Repeat the testing and recording using your LEFT hand.
WARNING OR CLUES GIVEN
7. Get your RIGHT hand ready to catch the ruler.
8. Have a partner hold a ruler even with the top of your fingers and thumb.
9. Your partner counts to three then lets the ruler drop on THREE.
10. As fast as possible, catch the ruler when your partner lets it drop.
11. Repeat four times and record the number showing above your finger and thumb.
12. Repeat the testing and recording using your LEFT hand.
Results
Centimeter Reading Above the Thumb
Type of
Drop
Average
Trial 1
Trial 2
Trial 3
Trial 4
Drop
Distance
(cm)
Right Hand
No
Warning
Left Hand
No
Warning
Right Hand
With
Warning
Left Hand
With
Warning
To calculate the reaction time
Reaction Time 2 = (2 * Drop distance) / 981 cm/s2
Analyzed Data
Calculate the average reaction times
Conclusion
1.
2.
3.
4.
5.
Why is 981 cm/s2 used in the calculations (hint: think in terms of gravity).
What was your best average reaction time?
What was your worst average reaction time?
Explain how you could improve your reaction time?
How would this experiment differ if it was conducted on the moon?
Reaction
Time
(seconds)