Xref: utzoo sci.physics:6707 sci.electronics:5727
Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!rutgers!att!ulysses!sfsup!bobp
From: bobp@sfsup.UUCP (+Phillips R.)
Newsgroups: sci.physics,sci.electronics
Subject: Re: PUZZLE
Summary: If it is an attempt to cheat, it is a pretty feeble one.
Message-ID: <5057@sfsup.UUCP>
Date: 31 Mar 89 20:29:22 GMT
References: <24615@pbhya.PacBell.COM> <9916@bloom-beacon.MIT.EDU> <746@aoa.UUCP>
Organization: AT&T-BL, Summit N.J. USA 07901
Lines: 26

In article <746@aoa.UUCP>, carl@aoa.UUCP (Carl Witthoft) writes:
> In article <9916@bloom-beacon.MIT.EDU> yphotons@athena.mit.edu writes:
> >Have any ideas??????
> >
> >A recent MIT physics (freshman) extra-credit problem: Given 2 small
> >rectangular magnets, 2 paper clips, 2 thumb tacks, approx. 5 feet of
> >wire, a small block of wood (4"X2"X.5") build a DC motor running of 1
> >1.5V that can at least reach 2600 rpm. The use of glue, tape, etc in
> >the final product will disqualify you. Only the above mentioned items
> >can be in the final product. The use of a drill, saw, etc.  in
> >building the motor is ok.
> 
> This is clearly a blatant attempt to get net physics gurus to help
> this student cheat in class :=).  
> Alix' Dad ( Carl Witthoft @ Adaptive Optics Associates)

If it is an attempt to cheat, it is a horribly feeble one.  I took this class
(mumblety-mumble years ago) and there is no real trick to getting the motor
going.  2600 rpm is easily attained.  Besides, when I took it, a student's
motor beat the crap out of the prof's.  
To the original poster, if Walter Lewin is still teaching that class, enjoy it;
it is the BEST class in the entire physics sequence (or, at least, it was once
upon a time).

Rob Phillips
Real World