Date: Fri Oct 9 09:55:18 2009

Author: Richard Berg

Subject: Re: Be careful what you ask for (1H10.20)



I believe that if you make a large concave sail you may deflect the air in
the direction opposite the air coming from the fan, and thus the motion of
the cart would be opposite that of the motion with no sail. My
recollection is that one of the references in our demonstration discusses
this effect:


On Thu, 8 Oct 2009, Dale E. Stille wrote:

> Cliff,
> Depends.....Is he putting the cart on a boat or raft......
> If not then he will be disappointed and we get the chuckle.
> Still envious of the new digs......
> Dale
> wrote:
>> A faculty member asked me to make a curved sail for the fan cart this
>> morning. I am wondering if he really thinks the cart will move.
>> Cliff

Dr. Richard E. Berg, Professor of the Practice
Physics Lecture-Demonstration Facility
U.S. mail address:
Department of Physics
University of Maryland
College Park, MD 20742-4111
Phone: (301) 405-5994
FAX: (301) 314-9525