Hi I am Jared. welcome to Fun Science Demos.
Check this out.
How did I do that? What was going on there? Was it magic?
No it was science. What you did not see me
do is rub this straw on this fur and charge it up.
Well, what do I mean when I say charge it up?
Well, through science we discovered
that all matter is made of positive and
negative charges and sometimes some of
that matter we can actually rub off,
only the negative charges, and that
allows us to do some really interesting things.
Remember, by me rubbing this
straw on this fur, I am putting more
negative charges on the straw, and
through science we have discovered that
positive and negative charges attract.
They come together. Think of it like this:
When the charges are different they want
to come together, but when the charges
are the same they want to push apart, and
scientists call that static electricity.
So now let us take a look at this. so I
have a can, and remember we said that all
matter is made of positive and negative
charges. this can is not charged, so it is
made of positive and negative charges.
Now watch what I do here. I am going to
rub this balloon on the same fur that I
rub the straw, and it is going to pick up
a whole lot of extra negative charges.
What do you think is going to happen when I
take this balloon and put it toward the
can? will the can push away, or will the
can roll toward the balloon?
Let us take a look and find out: here we
go, negative charges on the balloon, the
can is made of positive and negative charges.
What just happened there?
The positive charges on this can were
attracted to the lots of negative charges on this balloon. Let us see if we
can do that again, and see how fast we
can get this can going and maybe...
maybe race it off the table
Can races with static electricity.
So remember we said all matter is made of positive and
negative charges, and that also holds
true for liquid matter here. I have a
container of water, and have a cup with a
hole punched in the bottom. I am going to fill
this cup with water,
hold it up, and let the water drip out
the bottom of the cup, and then hold my
balloon up to that stream of water.
Let us see what happens. is the water
going to be pushed away from the balloon?
or is it going to be pulled toward the balloon?
so, I am going to rub the balloon
and charge it up with lots of negative charges.
Hold up my cup, and you can see the water
is pulled toward the balloon, so what does that mean?
Well, I had a lot of extra negative
charges on here. What kind of charges attract?
Opposite charges attract, so that means this water must
have lots of positive charges, so what
does that mean? That means as I rub the
balloon on the fur, and i charge it with
lots of extra negative charges, if that
water is pulled toward the balloon, that
water must have positive charges in it.
So we know that balloons can pick up
extra negative charges, but I have to
wonder, can other things pick up extra
negative charges? so to test this out we
have lines of just torn up little paper
called confetti, I have a comb, a plastic
fork, and a plastic bat. instead of using
fur we are going to try using wool, just
wool fabric, so let us check it out.
Let us start with the comb, pick the comb up.
I am going to rub the comb on the wool,
charging it up with extra negative charges.
What do you think is going to happen when I
pass it over the torn up pieces of paper?
it is kind of jumping onto the comb, but
is it really jumping? no. positive and
negative charges attract. It worked!
Let us try the fork, charge it up with
lots of extra negative charges, pass the
fork over and you can see a few bits of
paper are attracted to the negative
charges, now let us try the plastic bat.
We charge it up, and you can actually hear
and see the paper stand on end as I wave
it over and it jumps right onto the bat.
it did not jump, the positive and negative
charges are attracted to each other. so
finally take a look at this game that we
made up using static electricity. we call
it sharks and minnows. I have some sharks
made of tissue paper hanging from this
crate, you could hang them from your desk
and let them drape down toward the floor, and then I
have a little dish of what I call fish
food. it is just the confetti we used in
the other demonstration, and then I took
the straw we used from the very
beginning, I cut out a little styrofoam
fish, I taped two straws together.
Here is the minnow. Here are the sharks,
and the this is how it works.
The fish food goes in here. The idea is
you have to charge up the minnow straw,
getting lots of extra negative charges
on this, and I have to try to get some of
the food to be attracted to the minnow
without getting eaten by the sharks. as
soon as the Sharks touch the minnow
I am out, so let us see if we can do this.
and reach in,
He got me try over here! He got me!
Reach in this way...
Static electricity could actually be a
fun game. Sharks and
minnows was a game we created using
static electricity. Can you create your
own game using static electricity?
What if instead of tissue paper sharks
what if I hung up soda cans?
I do not know, give it a try.
Science is so cool. If you want to learn more about
static electricity, check out our links
in the video description.
Thanks for watching.