Physics Experiment ~ How to Determine a Person’s Reaction Time ~ #GluenGlitter #CBias

Since we homeschool we’re always doing science experiments. High School courses require a lab element so we do at least two every unit, sometimes three! We don’t always do ‘projects’ in conjunction with them – but it’s fun to use Glue ’n Glitter and put together a visual board when we’re using measurements to table and/or graph the experiments.

We just started our High School Physics course and are on the second chapter. We had an experiment this week on “How to Determine a Person’s Reaction Time”.

If you’d like to do this experiment, this is what you’ll need:

Ruler, preferably metric
Another person to help 🙂


1. Get your helper to hold on to the ruler at the very top, vertically, with arm held straight out. Face your helper and stand slightly less than an arm’s length away from the ruler.

2. Using the hand you write with, hold your thumb and index finger about 3 cm apart with the ruler in between them. Line them up with one of the measurements lower down on the ruler and remember what measurement you chose.

3. Tell your helper to release the ruler without telling you when. As it is falling, grab the ruler between your thumb and finger.

4. Subtract the measurement between the one you ended on from the one you started on (ie. if the measurement you chose to ‘hover’ over was 22 cm on the ruler and you ended up holding the ruler when it fell at 4 cm – your ending measurement would be 18 cm.) If your ruler is in inches multiply your result by 2.54 to get the answer in cm.

5. Repeat this five times to get an average. Using the average, determine your reaction time with this equation:

t= time (in seconds) dcm = (average of your distance in cm) (980 cm/sec2 is acceleration due to gravity).

6. Now do the experiment again with the roles reversed. You drop the ruler, and your helper catches it.

7. See who has the faster reaction time.


Now record your results using graphs, tables or charts and your conclusion on an Elmer’s Corrugated Tri-Fold Display Board. These are great for all kinds of school projects. They’re sturdy and since the sides fold in, it can stay flat and protected during transport.

Titles can be made bold with 5 pack Painters Markers – Bright. They are really easy to use, and are so much cleaner than paint! These will definitely be used more often for projects of all sorts in our home.

A little bit of #gluenglitter from Elmer’s 3D Washable Paint Pens helped the titles stand out even more on Amber’s project board.

Amber made the graph pertinent to the experiment by showing the average results in a ruler graphic. She added a few stickers to it that she found in our scrapbook box as well. I especially like the cute little “Augh” sticker she pasted below her results – she wasn’t too pleased to find out that her Dad still had a faster reaction time than she did!

Elmer’s Walmart selection is pretty good, which is where we bought the supplies we used. You can see photos from our shopping trip for it on my Google+ wall, click the photo below to be taken to it!

Google+ Photo Story

“This shop has been compensated as part of a social shopper insights study for Collective Bias. #CBias. Opinions are my own.