Ideas for an experimental project

[Chen]

Hi,

I'm taking a course (lab) in which I'm required to think of an experiment, design and build it, forecast its outcome, conduct it, and analyze the results. Sadly I'm having a hard time thinking of any worthy ideas for such a project...

The experiment should be on the subject of classical mechanics, although if I really want to (i.e I have a good enough idea) I can deal with subjects in other areas as well. I'm free to use anything at our lab, so equipment shouldn't be a problem (to a certain limit of course). The subject of the experiment should be substantial and not too simple (again, to a limit). I don't mind too much if the theory behind the experiment is a bit complicated - whether from the physical point of view or the mathematical - as I'm willing (and looking forward to) self-studying the required tools if needed.

I've Googled for the past week or so but my search wasn't very focused and I couldn't find anything I liked. So - anyone has any ideas for me? Just throw at me whatever you can think of, I always belived in brainstorming.

Thanks,
Chen

(Note that this is NOT a "science fair project", not even close. So please don't refer me to threads dealing with that subject. )

 

[Integral]

Chen,
What level are we talking about? High school? 3 yr University? It makes a lot of difference.

 

[PBRMEASAP]

Here's one I would do if given the materials to do it. Make a pendulum in which the arm is a spring. It would be best if you had a selection of different springs, ranging from very stiff to not-so-stiff. Then investigate how the period of the pendulum swing varies with different choices of spring constant. You might even see what happens if you let the mass go with the spring in a stretched position. Complicated motion should result.

Also, anything involving a spinning top/gyroscope is a winner. The nice thing about these is that you can go into as much or as little depth as you please, and still come out with something worth doing.

 

[Chen]

Chen,
What level are we talking about? High school? 3 yr University? It makes a lot of difference.

I'm currently studying for a first degree in physics, 3 year program. It's my second semester, and formally we've only studied classical mechanics and special relativity so far. Thanks for your help. (And like I said I'm willing to self-study other subjects if necessary.)

Oh and another thing - the general idea here is to take a certain aspect of physics, study it, and through experiment compare theory to practice. Ultimately that's what we're taught to do here.

Here's one I would do if given the materials to do it. Make a pendulum in which the arm is a spring. It would be best if you had a selection of different springs, ranging from very stiff to not-so-stiff. Then investigate how the period of the pendulum swing varies with different choices of spring constant. You might even see what happens if you let the mass go with the spring in a stretched position. Complicated motion should result.

You mean something like this, right?
http://www.myphysicslab.com/spring2d.html

Also, anything involving a spinning top/gyroscope is a winner. The nice thing about these is that you can go into as much or as little depth as you please, and still come out with something worth doing.

Thanks, I'll look into those two subjects.

In past years someone used a stretched membrane and then experimented with the motion of marbles on that membrane, to study gravity. I thought maybe to take that idea a step ahead, and try to simulate electrostatic interactions by stretching the membrane up-wise as well. The only problem is that I'm not sure if superposition would work here very well, because of the nature of the membrane... (And then there's also the problem of making sure the membrane surface is stretched in a way that would result in a 1/r^2 force, but I suppose that's workaround-able.)

 

[Danger]

There you go then--lots of good ideas. What I was going to suggest is to delve into one of your hobbies or other personal interests and investigate some aspect of it that not only satisfies the experimental requirements but also aids you in your proficiency. Of course, I don't know what your interests are. For example: a guy spent a lot of time figuring out the proper way to toss a horseshoe to ensure that it hits the peg right-end-to. Or investigate the modifying effects of physics on the initial geometry of a pool game. Or maybe the effectiveness of various lubricants in high-speed bearings. Good grief, man... the list is endless. Just look around you.

 

[PBRMEASAP]

You mean something like this, right?
http://www.myphysicslab.com/spring2d.html

Yes, that's exactly what I was talking about. That is a very cool simulation. Thanks for posting that link. Actually, the equations of motion given there are incomplete--the inertial forces (centrifugal and Coriolis) are left out. In light of that, it is amazing to see how complicated the motion is, even when "simplified". Still, those equations should give a reasonable approximation in the limit of a stiff spring with small amplitude.

 

[PBRMEASAP]

Oops. My last post was incorrect. Since the forces were computed in cartesian coordinates, there are no inertial terms. So the equations given are not incomplete. Sorry about that.

There are also many other neat simulations on that site that might suggest good experiments.

 

[mapper]

Take a metal ball barring/marbel. Set up multiple inclines, each at the bottom of the inclines have different surfaces. Sand, tape, liquid... Easy to set up/measure/forecast outcome. Did that in grade 7 i think. hehe

 

[xJuggleboy]

Try a harmonograph! They are bunches of fun!