Physics & Physical Science Demos, Labs, & Projects for High School Teachers

Homemade Hooke’s Law Device

Posted on: March 5, 2012


I like saving money for my school.  Nothing against Carolina Biological, we’ve been really pleased with their equipment and service, but sometimes their stuff is just way overpriced.  Their Hooke’s Law Device is $35 each.  I made a similar set of devices for a couple of dollars using what we already had in the lab and classroom.

My device is made with a ring stand and small rubber bands to hold a ruler in place.  I used a pendulum clamp as the top support, but any clamp will do.  To connect everything, I used a bit of chain that comes with a shop fluorescent lamp and opened up the links.  These are in an S shape and twisted to be offset by 90 degrees.  You could just as easily purchased a package of S hooks at Home Depot for a couple of dollars.  At the top, I hang one side on the clamp and hook the spring over the other opening.  Same on the bottom, the hook provides a place to hang a weight.

We use hanging weight sets, I just didn’t have them hand for the picture, this is one of my 500g medicine bottle weights.  The springs come from Harbor Freight.  They have a box set of 200 springs for about $5.  Lots of springs to play with, many look alike but have very different spring constants.

Indicator made on the 3D printer

 

My “indicators” were fabricated on the 3D printer, but you can just as easily make the same thing with two Popsicle sticks and some glue.  Drill the holes or it will split.

That’s really the whole thing.  I found that if I spun the whole setup one rotation CCW, the spring would try to rotate clockwise, holding the indicator against the ruler and making it much easier to read.

I’m planning on adding a scatter chart to this lab.  The students will enter the points in Excel to create the chart and then plot a trendline.  We can then use the first order trendline to determine an unknown weight based on the distance the spring stretched.  This setup was inexpensive and effective.

Advertisements

1 Response to "Homemade Hooke’s Law Device"

I use a 5 N spring scale, and put masking tape over the Newton part. A pen to mark the stretch on the masking tape. Graph stretch in cm v mass in g. Beautiful straight line.

We then use a rubber band to compare the stretch with the same masses. Not always so straight – oh the irony, the ‘elastic’ band is not elastic.

What do you think? Your opinion matters, leave a reply.

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

What’s New in 2013/2014?

Every year brings a change, this one is no exception.

I will be picking up the sophomore honors Algebra II class to keep them separate from the juniors. This should help accelerate them and put them on a stronger track towards Calculus. Looks like there will be only one section each of Physics and Calculus, but still two of Robotics & Engineering.

Hot topics this year are going to be the Common-Core Standards, Standards-Based Grading (SBG), improving AP Calculus scores, and somehow adding Python, maybe as a club.

Polls in the sidebar

Just a quick poll to help me understand who is stopping by my blog.

Yeah sure, lots from America, but look who else is here…

If you are badly in need of more email or for some reason jonesing for a physics fix, enter your email address so I can bother you with my newest rant on science.

Join 312 other followers

Blog Stats

  • 1,252,284 hits by nerds like me since June 1, 2008
March 2012
M T W T F S S
« Feb   Apr »
 1234
567891011
12131415161718
19202122232425
262728293031  
%d bloggers like this: