Chronology | Current Month | Current Thread | Current Date |
[Year List] [Month List (current year)] | [Date Index] [Thread Index] | [Thread Prev] [Thread Next] | [Date Prev] [Date Next] |
What would happen if an unstoppable force hit an immovable object?
Hmmmm...
It was an odd number, so the answer was in the back!
Are you going to leave us in suspense, Anthony? What was the answer?
:)
On Mon, Jan 22, 2018 at 11:27 AM, Anthony Lapinski <alapinski@pds.org>
wrote:
The universe is complicated. Nobody fully understands it (or ever will).by
Most intro courses try to simply things.
In my college logic book there was this question:
What would happen if an unstoppable force hit an immovable object?
Hmmmm...
It was an odd number, so the answer was in the back!
On Mon, Jan 22, 2018 at 12:11 PM, Philip Keller <
pkeller@holmdelschools.org>
wrote:
I have run into this issue in other contexts. You try to make a point
itraising a counterfactual -- what would happen if the universe were
different than it is? Sometimes this works, but as a teaching method
upfrequently runs into trouble. Your students (or your colleagues on the
list serve) start thinking about the implications of what you have
suggested and they start finding all kinds of ways that your little
counterfactual leads to weird results. It is tempting to try to prop
whatyour original questions: "No, no, no -- I just want you to consider
other!"would happen if the universe were different in the one way and no
theBut it is no use...your audience persists in their reasoning and yourbut a
counterfactual leads to not just the limited conclusion you hoped for
lot of other conflicts with the laws of physics.
But maybe that is not the worst thing that can happen. It shows that
thatthreads of the tapestry are woven together.
In case you are curious, here are two counterfactual-type questions
Iof
tried (and failed with) in the past:
What would happen if an object exerted forces on other objects but
experienced no reactions?
What would happen if induced current flowed in the opposite direction
wrote:the one indicated by Lenz's law? (Discussions here on this list helpedme
with this one.)
On Mon, Jan 22, 2018 at 11:26 AM, Paul Nord <paul.nord@valpo.edu>
thethat
John,
It seems that the physics concept Hewitt is trying to show is simply
such'liquids cool by evaporation because the faster molecules leave the
surface.' That concept seems fundamentally sound.
We might like to add a few caveats about surface tension, energy
distribution, and equilibrium. But isn't it basically true that if
a
strange liquid existed, it wouldn't cool by evaporation?
Paul
(P.S. I had a bigger gripe with December's Figuring Physics when it
referred to the momentum of the windshield and not the momentum of
attachments,conceptuallyentire car. That was an odd mistake for Hewitt.)
On Sat, Jan 20, 2018 at 10:18 PM, John Denker via Phys-l <
phys-l@mail.phys-l.org> wrote:
On 01/20/2018 08:59 PM, Jeffrey Schnick wrote:
(I think the explanation given in the Physics Teacher is
_______________________________________________correct.)_______________________________________________
It's not correct, conceptually or otherwise.
As Robert Cohen pointed out at the beginning of this thread,
when the molecule leaves the liquid, it loses its binding
energy (van der Waals or whatever). If it loses energy
but there is no cooling, what happens to conservation of
energy??????
Also, if the explanation were correct it would apply
equally to evaporation (sublimation) from a solid.
It's even more obviously wrong in that case.
_______________________________________________
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l
--
<http://www.pds.org>
<https://www.facebook.com/princetondayschool>
<https://twitter.com/PDSPanthers>
<https://www.youtube.com/channel/UCVE-nTva0BlK0rT6vayqpIQ>
<https://www.instagram.com/princetondayschool/>
*CONFIDENTIALITY NOTE:* The information transmitted, including
is intended only for the person(s) or entity to which it is addressed and_______________________________________________
may contain confidential and/or privileged material. Any review,
retransmission, dissemination or other use of, or taking of any action in
reliance upon this information by persons or entities other than the
intended recipient is prohibited. If you received this in error, please
contact the sender and destroy any copies of this information.
Please consider the environment before printing this email.
_______________________________________________
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l
Forum for Physics Educators
Phys-l@mail.phys-l.org
http://www.phys-l.org/mailman/listinfo/phys-l