Hi guys welcome to Beals Science, I'm Craig Beals. You know we have found ourselves
stuck indoors like much of the rest of the world is right now with this
coronavirus thing, but we're making the best of it and so we decided we would do
some simple science today that you could do at home. And, all you're gonna need to
do these awesome physics experiments is one of the following or all of the
following. This stuff! Bread clip, a pack of gum, if you've got these foil gum
wrappers, and a bottle. Specifically, we want the bottle cap. Let's learn some
science together and make some projectiles out of regular old kitchen
stuff. Let's kick this off with the bread clip catapult
that's the little plastic clip that keeps the bread fresh. We're gonna split
that in half so now we have two little projectiles. And the way you put it on
your finger is really what makes this work, you've got to hook it up underneath
your fingernail and then just fling the thing. I collect these things all the
time, drives my wife insane, but I keep a collection around the house so that I
can shoot these at people, if I ever really needed to. So, you can see how to
clip this on your finger and believe it or not these things go! Like, they'll go a
long way, and they actually travel very fast! And with a little practice you can
get pretty accurate too I hit the camera on that one. I thought. here we go. let's
turn this into a science experiment and really see if we can figure out the
velocity or the speed. I put a meter stick up on the fence and then I've got
a phone running a timer, because for velocity we need distance over time.
That's also called the speed. I'm using another camera from a phone, you can do
this at home! This is a really simplified way to figure out the speed of an object.
So we can see when it crosses the zero mark it's at time: twelve point two two
seconds, it crosses the 90 centimeter mark at twelve point two seven seconds and
we've gone 90 centimeters. that's 40 miles per you, that's 64 km/h!
How are we getting those kind of speeds? Well, it has to do with rotational kinetic
energy. When my finger comes flying off my thumb it's providing energy or a
force that goes with the clip. Now, the clip would just stop with my finger, but
Newton's first law says an object will remain in motion unless acted on by an
outside force. And, since there's no outside force, it keeps going. I'm going
to show you a handy dandy trick. You've got all these people running around with these
bottle openers on their hands so that they can open up bottles these days. You
thought it was to show a sign of marriage, but turns out it's just a
bottle over. The reason this works is also explained by physics. This is just
leverage. So I'm using my finger and then the ring as a lever to pry something
open. Now, to get it to fly I've got to hold it in a very specific way. Basically
I'll be snapping my fingers and then I'll just have the bottle cap in between
my snapped fingers.That provides the rotation, the energy, the rotational
motion, to get it to fly off my fingers. And, as you can see, it travels along the
path of my forearm so if I want to shoot this thing straight or shoot it away
from myself I got to get it up next to my ear and then I'm gonna point my elbow
and that's where the bottle cap should end up. Again this one takes some
practice just like the last one but once you get it down this thing will really
go and you can get to be pretty accurate with it. Physics explains why this works.
We're adding energy, rotational motion, into that bottle cap, and it would stop
at the end of my finger but Newton's first law says it will remain in motion
if nothing causes it to stop. Now, I figured, let's see if we can get this
thing to fly at the same speed as the bottle cap. We got it to go about 1 meter
in .06 seconds that's 60 kilometers an hour or 37 miles per hour
that's fast! Now, what I'm wondering is, can you beat it?
If you set this up at home could you beat me? My challenge to you is: get that
bottle cap and get that bread clip to go faster than I did and then tell me down
in the comments how it turned out. Let's build a rocket out of a gum wrapper!
Sounds good doesn't it? You'll need gum that's got a foil wrapper on it and
you're just gonna take that wrapper off and put it around your finger, okay? Wrap
it around there so that you make a nice tube and you want that secured pretty
tightly. Then you got to take the top pinch it nice and tightly and then roll
it up ever so slightly and get it clamped down. Our rocket is gonna fly
using the principles of volume and pressure or changes of volume and
changes in pressure. Now if I change the volume of the air in my hand, in other
words I decrease it very rapidly, it's gonna cause an increase in the pressure
of the air inside my hand. Now that airs got to go somewhere and if I have my
little gum wrapper rocket on top it's gonna come shooting out because of the
change in pressure! My kids were helping me this day and my son said, "Oh
let me try I can do that!" Maybe he could use one more lesson. There's the one you
made. Put it in here like this. You watching? You get that gap, I'm just going to try to
close that gap. Ready? There you!
Where did it go?
He eventually got it!
Hey, we hope you learned some science that you can try out at home especially
if you're stuck at home right now with all this corona virus madness. And we
also hope that you stay well. But the reason we always make these little
videos is to remind you to "Keep on Learning!" Thanks for watching...let's go eat some
bread...