Date: Fri Feb 19 10:56:28 2010

Author: Jerry Hester

Subject: Re: Fwd: demo I need


Thanks for the many suggestions and discussion.
For now, Murray is going to go with the ball drop cart although it
doesn't quite get at what he wants.

I hope each of you have a great day.
Jerry H.

At 03:27 PM 2/18/2010, Jerry DiMarco wrote:
> This sounds like a problem in need of clarification. One
> possible misinterpretation has already been described. I'll bet
> other students visualized a dump truck traveling down the road with
> the box raised, dumping its load. In that situation, the departing
> sand does give the dump truck a shove in the opposite
> direction. The DCS has a couple demos that either sound very
> similar or could be adapted to do what you want. They are:
>1N21.26 thrust cars
>1N21.45 vertical catapult from moving cart
>Don't know how much time you have to develop this but good luck...
> Jerry D
>At 2/18/2010 09:12 AM, you wrote:
>>>Hello Tapplers,
>>Do any of you have ideas regarding the best way to do demo described below?
>>>I would like to demonstrate that sand falling out from a moving
>>>dump truck falls at the same horizontal speed as the truck, and that
>>>the truck does not change speed as a result of losing the sand.
>>>The "howitzer and tunnel" sort of does this, but not quite.
>>>Got any ideas?
>>>A surprising number of my students think the truck should speed
>>>up. It's interesting, because when I changed the terms their answer
>>>changed. That is, when I described a boy on roller skates dropping
>>>a ball, they all said the ball would move forward with the boy and
>>>fall at his feet.
> Jerry DiMarco
> Manager of Lecture Demonstrations and Instructional Labs
> Montana State Univ., Physics
> Dept.
> Bozeman, MT
>Our Motto: "Find your inner demo."

From Fri Feb 19 10:56:28 2010
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