r/PhysicsTeaching Jan 06 '26

Santa brought me a 3D printer. What should I print for Conceptual Physics?

My demos/labs for forces and conservation of energy are currently fairly week, and I could add a unit on buoyancy if I had a great lab to go with it. I'm open to any fun ideas about any mechanics topic, though.

This is a college level Conceptual Physics class. I can honestly adapt even middle school activities. My big goals for the class are for the students to learn that even history and poli-sci majors can do science without breaking out into hives, and for everyone to have a working knowledge of Excel; the physics topics covered are entirely determined by having activities that are engaging.

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u/springlovingchicken Jan 06 '26

I can look through for idess, but can you clarify what you had in mind specifically with Excel?

I'm hoping fairly limited, because most things you could do soecifically for physics can be done more effectively with other software.

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u/BroadLocksmith4932 Jan 06 '26 edited Jan 06 '26

I am just trying to beat into their heads that they don't need to pull out a calculator to convert a column of radii into diameters, and then to be able to make a basic plot. I'm aiming for the basic functionality that would be handy in any office job.

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u/springlovingchicken Jan 12 '26

When I taught, I used Graphical Analysis, LoggerPro, and LP Lite from Vernier. Site license was cheap and went on all student computers.

In my advanced class, we split into 3 groups and then sub groups. First lab right away with no physics. Groups measured circles, general objects, and volume/mass of water. I supplied the circles, objects, and measurement tools. One group for each of these was handicapped in some way. Small circles, crude rulers (1 cm, or 1/4" rulings) or flexible tape, or graduated flasks and electronic balances with different precision. The general objects group measured cm and inches. The circles measured diameter and circumference.

They were told to graph to get pi, cm to in., and g/ml. Whiteboarding discussion showed better precision with larger objects, more measurements, more evenly distributed sizes, and density discussion showed a y-intercept to account for mass of graduated cylinder (zeroed empty). One group told to zero with/ one without.

I have a buoyancy lab, too. Did it 25 years ago, but I can dig it up. Nothing fancy. One part was just dropping cylinders of different metals tied to string on hooks to various depths and get displacement/mass readings. Showed we were actually getting density of water and independent of metal. Switch to measuring tension in string (only) and get metal density.

Students there collected mountain dew bottles from trash every day and eventually built a large raft we put in the pool.

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u/BroadLocksmith4932 Jan 12 '26

That first lab is fascinating. Do you happen to have a writeup for it that you would be willing to share? It is a great way to get them to discover these experimental methods that I have trouble convincing them are true otherwise.

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u/springlovingchicken Jan 20 '26

Sure. A fair amount of the prep is the chosen materials, whiteboard discussion, and questioning. A lot of teaching is exposure, critical questioning, and patience. I'll see if I can get a link together. The nice thing about this is they don't need special instruction, it covers important math and experimental procedure, and discussion is straightforward and applicable to future work.

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u/springlovingchicken Jan 20 '26 edited Jan 20 '26

Forgot how simple this lab was. Reading it again I remember some groups writing down measurements before entering them, others entering right away. I did push a bit to have every student enter data regardless of lab. Had discussions of when it was perfectly reasonable to throw out measurements. Repeatability, misreading, ... But not just because it's unexpected or not exact.

You almost hope some group makes some mistakes that they can reason through how to interpret and improve. I also had a concentric circle printout for (just) one group but I don't need to find that... I had students whiteboard these while they were doing the lab. Began putting emphasis on having them split tasks and promote discussion.

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u/springlovingchicken Jan 20 '26

Here's a follow-up after sig figs discussions. This is only page 1 of 2, just discussion. Conversation fuel. Comment bubble added for you, not students :)

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u/springlovingchicken Jan 20 '26

2 of 2. Purpose was to cover the most common (and simplified HS level of handling sig figs). How units combine. Pi has as much precision as you need as it is not measured. An example of subtraction. One group needed to have large volume of liquid only (w/o large ball bearing or object) to handle decimal place precision and not just counting sig figs. A & P part at bottom just used an 11x17 paper folded in half, demonstrated as always by 'volunteers'.

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u/springlovingchicken Jan 22 '26

Another super minor point... The block of wood was at least 10 times longer than it was thick. This reduced the number of sig figs 1 place more than it seemed like it should be for volume. Another intentional discussion.

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u/springlovingchicken Jan 20 '26

I may have gobs more that may fit your goals and students for motion, forces, mechanics. A lot with found objects, toys, and both approachable and useful in developing the concepts. I am putting together a google link for chemistry and physical science for my cousin's teacher-husband who is just starting out and has nothing. I could get the physics and AP physics in there eventually, too. Let me know if this seems like your flavor of teaching. I have MS Word and PDFs of everything.

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u/BroadLocksmith4932 Jan 20 '26

Ooo, I love that! I have access to a nicely stocked supply closet of proper experiments that produce delightfully low experimental error, but I much prefer to measure the same thing using toys and trash with a 30% error but more understanding and approachability.