Who’s up for a challenge? Squeaks and I love to build things. Sometimes we build forts out of pillows … or
castles out of blocks…and sometimes we snap together plastic bricks to make spaceships! But, today we’re going to use cups. Yup, just cups! And Squeaks and I have decided to build the
tallest stack of cups that we can. We know from playing with blocks, that it’s
best to build our stack on a flat, hard surface…like a piece of floor that doesn’t have any carpet
on it. And to make things easier, we’re going to
use cups that are all the same size. And, we’re going to use plastic cups. Paper cups would work, too…just never glass. Looks like we’re ready, Squeaks. Let the cup stacking begin! First, we’ll start by putting a cup upside
down on our table. You can use the floor, or a table at home Next, we’ll put another cup on top. We’ll need to put this one right-side up,
so it doesn’t slide down on top of the first one. Now, we’ll carefully set another cup, cup
number three, upside down on top of number two. Cup four goes on top, right side up. Hmm, things are getting little wobbly. Cup number five goes on…successfully! Let’s see if we can put cup number six on
top… …and down it goes! So, by making a simple stack of cups, one
on top of the other, we were able to build a tower that was five cups high…. before
it fell over. But, what can we do to build a tower that’s
even taller? We’ll need to find a way to make our stack
of cups more stable. If our stack of cups is stable, that means
it won’t wobble and sway like our last stack did, so it shouldn’t fall over as easily! So this time, let’s try something different. Let’s start with three cups, upside down
on the table. Now we’ll put two cups — also upside down
— on top of those … and we’ll put one more cup on the top. Look, we made a pyramid! This stack is one…two…three cups tall. Do you see how our pyramid of cups is shaped
like a triangle? It has a big, wide base, or bottom. That wide base is a reason that a pyramid…and
our second stack of cups… is so stable. You can test this out for yourself. But not just with cups. With you! Stand up for a minute! Now, try to stand on one foot. Do you wobble back and forth a little? Now try standing on both feet. It’s probably easier to stand on two feet,
right? That’s because two feet make a wider base
than one foot. Your weight is spread out between both feet
instead of being all on one foot. The same thing is true when you’re building
something — whether it’s a stack of plastic cups, or a big-city skyscraper! In our first tower, the weight of the stack
was on the one cup on the bottom. But in our second try, the weight of the stack
pushed down on three cups that were spread apart, instead of one. A wide base helps to spread out the weight
of what’s on top of it, and makes whatever you’re building more stable. So let’s try one more building, using an
even wider base. We’ll put one, two, three, four, five cups
on the table. Then, we’ll pile four more on those…then
three…then two…and one on top. This time our pyramid is five cups high! In fact…if we start with even more cups
on the bottom of our pyramid, you can build even higher! That wider base makes it possible to build
a taller structure. A wide base is useful for more than just stacking
cups. Some of the most stable buildings in the world
are shaped like pyramids. This building is one of the tallest in San
Francisco…and is stable enough to stay up during an earthquake. So, are you excited to build your own stack
of cups? Ask a grownup to help you find some cups…and
you’re set to get stacking! Thanks for joining me on SciShow Kids! Do you have a question for us about buildings…or
anything else? If you do, ask someone to help you to leave
a comment on this video, or to send an email to [email protected]!