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Science Rocks!

Reaction Time


your results

Sent in by:
Kelsey of Incline Village, NV

Take action to time your reaction!

Materials Needed

  • ruler with centimeter marks
  • table
  • paper and pen for charting results
  • a different colored sticker or pen for each person



  1. Has anyone ever said, "Think fast!" and then thrown something at you? How quickly or slowly you react is called your reaction time.
  2. To measure your reaction time, ask a friend to help.
  3. You will need the reaction time chart below.
  4. Then draw a graph to record your results. Along the left side of the paper (the y axis) write the times from the reaction time chart in separate rows. Across the bottom of the paper (the x axis) write "Trial 1", "Trial 2", and "Trial 3" in three separate columns. You will record each other's reaction times on this graph to compare them when you finish testing.
  5. Now, sit in a chair with your arm resting on a table so that your wrist hangs off the edge.
  6. Your friend will hold the ruler so that it dangles above your hand. Make sure the end of the ruler is hanging between your thumb and finger.
  7. When your friend lets go of the ruler, try to catch it between your thumb and finger as quickly as you can.
  8. Compare the marking on the ruler where your fingers caught it to the reaction time chart. Your reaction time is how long it took for your eyes to tell your brain that the ruler was falling and then for your brain to tell your fingers to catch it.
  9. Make a mark on your graph next to the matching reaction time over the Trial 1 column.
  10. Try catching the ruler twice more, marking the results on your graph each time. Give your friend (or friends) a chance to test their reaction times.

Who has the best reaction time? Do your reaction times improve with practice? Did your reaction times vary a lot or were they pretty much the same from trial to trial? Are older kids faster than younger kids? How about your parents? Come up with your own questions. Then test them out, and send your results to ZOOM.

Some of your Results

Ashley, age 12 of Pittsburgh, PA wrote:
Older people are faster than younger people are. I thought that younger people are faster than older boy was I wrong.

Lidiette, age 13 of Bethlehem, PA wrote:
the first time I tried it I caught it at 17cm. im not so good at it. My older brother and sister caught it the fastest...(maybe because they are athletes)

Helena, age 16 of Memphis, TN wrote:
I did this experiment for a science project at school and I got 28 cm! I'm really bad at it! I found that the boys were faster than girls and that younger people were faster than older people.

Catherine, age 11 of Gulfport, MS wrote:
I caught it at. 5cm! That is awsome!!

Yann, age 12 of Miami, FL wrote:

Julia, age 13 of Austin, TX wrote:
Boys have faster RT than girls your reaction time improuvs as you get older

Dasha, age 12 of Atlanta, GA wrote:

Cathleen, age 10 of Dearborn, MI wrote:
i caught it at 2 cm!!!

Brianna, age 11 of Woodstock, GA wrote:
I got it a 4 cm!!! It was fun!!!

Fantasia, age 15 of Paterson, NJ wrote:
It was so cool!! I tried it and it was really fast. But I caught it at 2cm 1in. It was fun.

Matthew, age 12 of Quincy, MA wrote:
I was the fastest in my family!

Dana, age 12 of Winnipeg, MB wrote:
I caught the ruler at 5cm.

Amrinder, age 13 of Vancouver, BC wrote:
When I did this I caught the ruler at 2cm and 3seconds.

Grace, age 11 of Albert Lea, MN wrote:
Well I did it for a science project and im not quite finished with it but I know boys have a faster reaction time.

Grace of MN wrote:
I did it for a science project and boys do have faster reaction times than girls.

Treasure, age 12 of Memphis, TN wrote:
When I did it I missed it the first time then the second time I caught it at 5 1/2 centimeters.

Amber, age 13 of Kingston wrote:
Everyone that we read out had slow reaction times compared to our class, which was 19 seconds on average.

Kayla, age 12 of Ashville, OH wrote:
We seen that a lot of people missed it first but then caught it at around the 20-25 mark.

Hani, age 12 of Falls Church, VA wrote:
I tried compering the results with student athletes and students. The students caught it lower but slower than the student athletes. The athletes caught it higher but faster. I dont get how do the results make scence or not? Its some pretty weird results!!!

Emily, age 11 of Irvine, CA wrote:
At first I missed the ruler, but then I got it at 1 centimeter!

Hiroki, age 12 of Pleasant Hill, CA wrote:
My friend was doing a project on reaction times and my speed was 0.238 seconds.

Huy, age 11 of San Jose, CA wrote:
I did it and everybody in my house had and average time 18 seconds. I guess no one can get under 10 seconds

Omar, age 14 of Chicago, IL wrote:
I used a meter stick to measure how much time it took for me to react to the meter stick falling through my fingers and catch it. We then substituted my average of my 5 trial, which was 14. 6 cm, and substituted it into an equation given to us by Galileo. So we substituted into the equation T=square root of 2D/G, and we assumed that the acceleration of the meter stick was 10m/s2 after we get (square root of) 2*. 146m/10m/s2 =. 17s. This means that it took me. 17s to react to the meterstick falling through my fingers

Draven, age 8 of Schenectady, NY wrote:
I caught the ruler at 2 cetimeters!

Elizabeth, age 13 of Everett, WA wrote:
I'm left handed but I did better withmy right hand.

Timothy, age 13 of Harlingen, TX wrote:
I caught the first time at 6cm second time 4cm and the third time 7cm.

Amber, age 10 of Dawson, AL wrote:
Older kids have better reaction time then younger kids.

Jacob, age 14 of Portland, OR wrote:
With fast music, reaction times were much faster (I got. 095). People who where in Teenage years (Closest to 15) had the fastest times, regardless to music.

Hanah, age 11 of Attleboro, MA wrote:
I got 6 in my reaction time

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