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I'm a physics teacher and have an old bike in my possession. What are some neat toys I can make? Answered

I am in need of some demonstrations which can be made from old bike parts. Or, neat things to enhance my classroom would work as well (gear clocks which rotate, etc).



Lots of things: Reference frames, including video analysis (http://www.cabrillo.edu/~dbrown/) Torque - hang weights from pedals with bike in different gears Tensile/compressive forces - replace the bottom frame tube with a cable and pull scale Gyroscope - which will work better if you can get some extra mass on the rim (wrap fence wire many times inside the tire), put an eye hook in one of the handles to that you can hang it from a rope from the ceiling Gyro 2 - borrow a trainer (http://www.rei.com/product/680045) and go for a ride PE->KE - roll down a hill from various heights and compare distances to come to a skidding stop KE->Thermal - compare temp of rim/brake pads before and after stop Acceleration due to gravity - compare final v for heavy and light kids rolling down a hill without pedaling Inertia - video water spraying off spinning tire I'm working out a plan for using bicycles as the central experimental apparatus for the first trimester of my conceptual physics course next year.

Remove wheels - add wooden handle to axle - allow student sitting on revolving office chair to experience gyroscopic progression.

Just an observation -as a teacher you need to be thinking about what you have to teach a lot harder than you seem to be.

the correct, generic term is gyroscopic precession, not gyroscopic progression, and the specific technical term for this type of precession is torque-induced gyroscopic precession.

Although, imho, only a fool would use any of those terms to try to draw interest out of most 15-16 year olds, hence the use of "peculiar reaction"... it's not how smart the teacher looks or how commanding he or she is, it's how much he or she engages the student and how much the student learns.

elementary my dear watson...bicycle...neat things..classroom==> highschool, not condescending, misinforming, professorial attitude. Inspirational, engaging, and most important...accurate.

And that would go as well when drizzled over a young teacher as a young student.

With all due respect it's much better than inaccuracy and a cloaked slap on the wrist for what I would assume is simple, eager inexperience.

sincerly, son of teacher, grandson of two teachers, and btw, physicist.

It's a shame you don't have a second bike to work with...there are so many fundamental concepts that can be shown with a bike... If you *could get your hands on another...the wheel axle itself is a great teaching aid, for showing how bearing surfaces in rotating machinery is made...launch into discussions of the various types of bearing surfaces and how they are actualized... snip off the spokes from a wheel, disassemble the axle and wash thoroughly in solvent, give it a light coat of DW-40 or similar to keep it from rusting, and reassemble as a teaching aid. You can explode it as necessary for showing the structure of this type of bearing surface...as is the frontfork/handlbar section... touch on the derailleur and how it does it's job, both as a switching mechanism and as an idler to maintain tension in the drive chain... Reflectors and the ideas of reflection and diffusion...(aren't reflectors a simplified waveguide folks? Am I off-base there or is my memory and coffee working today?)

Oh, and as to the spokes themselves...it can also be noted that spokes are a method of reducing weight while maintaining load bearing capability ( not to mention how they are used to maintain the "true" of a wheel...a concept valuable in itself)....structural concepts...the frame itself is a comment on structure.. these might seem to be no-brainers, or whatever trivialization someone use to minimize their impact, but for a budding mind, they are things often taken for granted that once illuminated, can make the difference between generating yet another ignorant consumer and a great engineer. The impact of these "trivial" demonstrations on the young student can't be stressed enough. They shape the thinking paths while they can still be shaped...

In addition to the great suggestions below...use the front wheel as a gyroscope. put handles on the axle ends so people can hold it. then spin and see how trying to rotate it perpendicular to the plane of rotation causes a "peculiar" reaction from the spinning wheel....

Seconded! Classic demonstration. Good also to add a fender to prevent accidental skidmark to the users face :D With the front wheel gone, add a big dynamo (car alternator would work) to the rear tire, and show how a generator works.

Wave playing cards between the spokes to make the clicky noise. Ride around at different speeds and you can link the pitch of a sound to the frequency.

As seandogue already said, you've got to do the gyroscope. Sure it's a chestnut, but it's still really cool for a student to feel the torque in their gut.

I think a static electrical generator might be good, either V D-G or Whimshurst (trickier).
There's the old pedal-generator with variable load - nice if one of the loads is a fan cooling the sweating cyclist.
(This is a joke but I'd like to see it built)


that's called a " simulator"...;P all you need now is a POV riding video...

It's not a simulator - not sure were you're coming from on that? L

Bike with generator that drives a fan to cool the rider... "all you need is a POV riding video"...you don't get the joke? A simulator...as in a flight simulator or other, this would be a bicyclist simulator...nvm...joke lost

Ah yes I see what you mean now. L

I've seen some people use the bearings from bicycles to make small wind turbines (mostly good for demonstrative use). My vote: Use front wheel to attach handle bars in the middle to demonstrate rotational inertia. Use the rest as either a pedal generator or use the bearings for a small wind turbine.

I see no one said to introduce the concept of gearing using the bike's drive train....It's surprising how many people ride without even thinking about how the gears actually do their "thing"

Reminds me of the "FuMA Flier" which lived in my high school physics classroom -- classic little red wagon. Standard silly experiment was to take it out to a suitable hill, measure the slope, measure a distance along that slope, determine the mass of wagon and contents, determine how long it took to run down the hill using a stopwatch, change mass of contents and try again, plot and explain the curve (determining a reasonable value for resistance from friction and deformation of the rubber tires). I know, that doesn't help you.

maybe just a regular generator to power a lightbulb. or maybe multiple ones. the harder one petals the more bulbs light up. I think an air raid siren would be pretty awesome too