This summer we ran a day camp
here in Elliott County for kids from 4th
to 9th grade. The older kids made hot
air balloons from tissue paper glue and wire.
Then they launched them
in front of the school. Most flights were
tethered so that they could recover them to fly again. One free flight went
over the school and landed safely so it too could
take another flight.
And here is a video of
one of the hot air balloon launches.
The younger kids took a
look at how 3D pictures and movies are made. Some systems require
special glasses, red/cyan for this one of the
junior campers. If you can't find a pair
but have red and blue markers and a piece of
thin plastic like is used packaging you can make red and squares to
look through. Color the plastic as
evenly as you can for the best result.
Or you can cross your
eyes while looking at this pair of
pictures. With a little practice
you will be able to see a third picture appear
between them in 3D.
A little puzzling.
Nim, Tangrams, and eight queens challenged
campers.
Here is a more or less typical moment in a class.
We did some chemistry to
make some goo.
That could be used to
blow these amazing bubbles.
Some parents got to try
as well.
We tried some standard
soap bubbles.
Then some kids were able
to put others inside bubbles.
We all took a trip to
COSI in Columbus Ohio.
Exhibits included hot
air balloons, the brain and an air pressure
canon.
This huge granite ball
is supported by water pumped under it. Since it only touches
the liquid there is very little friction and it
can be turned with little effort.
Some of our campers got
to help with the Electrostatic Generator show. They found out that like
charges repel and just what electricity feels
like.
Standing in line for the Centripetal Generator. . This machine spins fast
enough to pin you to the wall then when you are
getting used to that the floor drops about 2 feet and you are stuck
there. When the rotation slows
you slowly slide down the wall.
If you were
a camper you
might be able to recognize yourself on the
ride in this video.Back
at camp the morning group
had built water rockets and now they were about to launch them.
If
you know how far you are from the launch point just measure the angle
from the ground when it is at apogee and you can calculate how high it
went. You can also get the
elevation and azimuth from two points on a known baseline to make an
even better measurement.
Sit on a skateboard and
push two bowling balls back. You have just
demonstrated what makes a rocket go. There are lots of ways
to look at it: For
every action there is an equal and opposite reaction, unbalanced forces
at work, force equals mass times acceleration, and conservation of
momentum
Hold two liters of water
out to your side, sit on a rotating chair and pull them in. You will feel yourself
spin much faster. You have just
demonstrated the conservation of angular momentum.
We investigated levers. With the fulcrum in the
middle the larger force wins. But move the fulcrum
toward one end and we have a mechanical advantage that lets a small
force overcome a larger one. The trade off is that
the small force must move through a larger distance.
They had no trouble
lifting me if I was close to the fulcrum and they were far from it.
We were able to put a
known force on two eggs supporting one end of this lever. In the first picture the
eggs are holding up half of the weight of the lever and half of the
weight of the camper. By keeping track of the
weight and positions of the campers on the lever we found that these
eggs could hold about 200 pounds.
We also found that when
one failed it made a mess.
A spinning gyroscope
moves in strange ways.
If you are sitting on a
chair it will turn when you try to change the axis of the gyroscope. Very surprising and fun
too.
As surprising as it may
seem a light rubber ball and a much heavier bowling ball fall at the
same rate.
We measured how fast the
campers could run. Look at that
determination.
We used this device to
measure how far away we were from several objects without going to them. Again a known baseline
and measured angles were all we needed.
Cartesian divers made
from straws and clay or soy packets and paper clips were one of the
last projects.
We did lots more too. I think that all the
campers had a good time. I know I did.
The
www.mrtc.com/anvk/ web site by Alan
Kuehner is licensed under a Creative
Commons License.
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