Re: [Phys-L] Explaining Gyro Force to Motorcyclists

[John Denker <jsd@av8n.com>]

On 1/14/22 10:41 AM, Bill Norwood via Phys-l wrote:

> I need a list of references about how the gyroscopic force presents a
> hazard for uninformed motorcycle riders.

Suggestion: Skip the theory. Instead do the experiment.
That is, make yourself a handle that attaches to the hub
of a bicycle wheel. Let each student do the experiment:
hold it by the handle, give it a good spin, then wiggle
the handle. This is a memorable hands-on demonstration
of the sign and magnitude of the effect.

> My guess is that motorcycle deaths could be reduced by 25% if the
> riders were aware of the gyroscopic force hazard.

I agree with Dan M., that hypothesis is implausible.
The effect is not big enough.
You would have to lean into the turn anyway, with or
without gyroscopic precession.

People have done experiments with big gyroscopes attached
to the bike, counter-rotating or otherwise, and it doesn't
make much difference, within reason.

===================

Suggestion #2: If you insist on doing theory, YMMV but
long ago I gave up on cross products. I have never been
able to explain the right-hand rule to anybody who wasn't
already a physicist, not in a way that they can remember
for more than half a day.

Instead I can explain what bivectors are. I can explain
that starting from scratch and then use that to explain
precession in less time than I can explain the right-hand
rule. With better results.
 -- Angular momentum is a bivector in the plane of
  rotation. Easy to visualize.
 -- Torque is a bivector.
 -- The two bivectors add edge-to-edge, just as surely
  as two vectors add tip-to-tail.

You can make a show-and-tell using index cards if you want,
but using your hands works almost as well.

Lurid details here:
  https://www.av8n.com/how/htm/motion.html#sec-angular-momentum