Inside: Explore balance and gravity with two clever science experiments that use everyday household items. They will show kids that science can be almost like magic!
We love taking Dr. Seuss as our inspiration for fun projects. Hands-on projects and experiments bring complex concepts to life and keep my active kids moving and learning.
There are so many fascinating topics inspired by reading Dr. Seuss’s books, but one of my kids’ favorites is balance. Ever since we read about the cat that walks into Sally and Sam’s house on a rainy day and starts balancing things, they’ve been using objects from around the house to experiment with balancing. You might find some inspiration with our The Cat in the Hat Engineering Challenge.
Today we are going to explore the idea that having as much weight on one side of the center of gravity as on the other is what balancing is all about.
Experiment #1: Can the tip of a pencil hold a fork and an apple?
Alright, let me just start by saying that this is not one of those projects where kids are asked to do the impossible thing, and after they try and try, you say, good try, now you know it’s impossible, that’s the lesson. In this experiment, even though it sounds impossible, you actually CAN balance a pencil in such a way that it holds a fork and a potato! And finding how it’s done is super exciting. Let’s do it!
What you need
A school pencil
Apples (small, firm apples worked the best for us)
A table fork
An edge of a stationary item like a table, a shelf, or another flat surface that can be used for balancing the pencil
Note: If you are planning to eat the apple, wash the pencil before use! We used all our mangled apples to make a fabulous apple crisp.
What to do
- Slowly push the pencil into the apple until about 2 inches of it sticks out the other side. You will probably have to move the apple back and forth before the experiment is over. Warning: don’t push the pencil while holding the apple in the palm of your hand. You don’t want to jam the pencil into yourself!
- Rest the pointed end of the pencil on the edge of a table. We ended up using an easel laid flat on the chair and weighted down with books. Warning: watch your toes as you let the apple go.
- If you did it right: the whole contraption collapsed on the floor. It looks like the tip of a pencil can’t hold an apple. How about adding a fork? Would it help? At this point, all my kids agreed that it will only make things worse. Actually, it’s the opposite; the fork will help us balance it all out. But don’t share this bit yet, let it be a surprise.
- Now, press the prongs of the fork into the side of the apple, BUT keep in mind that you want the fork to be the counterbalance to the weight of the apple, so it should be angled in the direction opposite from the pencil eraser (and parallel to the pencil tip).
- Again rest the pointed end of the pencil on the edge of a table. But WAIT!
- Before you let go, feel the direction in which the structure is going to move when you start moving your hands away. If it doesn’t feel like it will balance, keep adjusting the pencil tip, apple, or fork. Don’t do all three at once. Try each of the following in turn: (1) Place the pencil tip farther or nearer to the edge, (2) slide the apple backward or forward, and (3) pull the fork out and stick it in at a different angle. Now you can let go of your hand. Did it work?
- When it does balance, it looks like magic! It might take a bit of work to find that magic point. In our case, it took more than one apple, but we put all used apples to good use and baked them into a delicious apple crisp.
- You can now repeat the same experiment with a potato. Let me tell you: it’s much easier to balance a small potato than a medium apple, so if you’re going for a quick experiment pick a potato.
- What made this incredible balancing act possible? Having as much weight on one side of the center of gravity as on the other. That’s the definition of balance. You can read all about it in the Science Behind the Experiment section below. For now, don’t pull the pencil out yet, there something else we can try.
What if we add one more fork?
Oh, no! This is getting crazy. An apple and TWO forks?! It’s not possible. Right?
But you know you want to try it, don’t you?
Experiment #2: Can we balance two table forks, an apple, and a pencil?
What you need
A school pencil
An apple or a potato
2 table forks
Glass or any jar
What to do
- As in experiment #1: the pencil is pushed through the apple, and one fork is sticking out of one side of the apple.
- Now add a second fork by pushing it into the other side of the apple. Try to stick both forks at angles exactly opposite each other.
- Turn a tall glass over and place the tip of the pencil in the middle of the bottom so that the whole contraption stands straight up.
- If it doesn’t balance make some adjustments to the angle and location of the forks.
- Look at the balancing contraption carefully and answer this question: Is there exactly as much weight on one side of the pencil as on the other? If the answer is “yes,” you can let go of your hands and watch an apple and two forks balancing on the tip of a pencil. Magic trick? It sure looks that way, but it’s not magic, it’s basic science.
- Let’s take it one step further. Right now, the pencil is standing straight up, but now we are going to lean it to one side and balance it in that position. It’s certainly a challenge but I promise you there is a way to adjust the angle and the position of forks so that the pencil balances while in a leaning position – it’s science a-la-Tower-of-Pisa.
- This experiment demonstrates that balance depends not only on the mass of the object but on how it’s positioned relative to the center of gravity of a contraption.
The science behind the experiment
When ARE objects in balance? When the weight of an object is evenly distributed. The point of balance, or center of gravity, is that magical point where there is as much weight on one side as on the other.
The center of gravity depends on the position of an object. For example, a standing child will have a different center of gravity than a sitting child. In our experiment, an apple with one fork sticking out of it had a different center of gravity than an apple with two forks sticking out of it. And an apple with two forks had a different center of gravity depending on where these forks were inserted. Symmetrical objects usually have the center of gravity in the middle. Asymmetrical objects can have their center of gravity to the side, like the leaning tower of Pisa.
Is it easier to balance a few objects than MANY objects? Not necessarily. As you saw in experiment #2, adding an additional fork helped us balance. Some objects are tricky. They appear big but weigh very little, or they look small but are very heavy. We learned that when we tried to balance an ever-increasing number of items in The Cat in the Hat Engineering Challenge.
Repetition is the Key to Learning
After my kids learned what these two experiments were all about, they had even more fun with them. The next day they repeated it completely on their own and kept going for a very long time. They didn’t stop at balancing apples either. Oranges, potatoes, any fruits and root vegetables they could find were soon added to the experimental arena. It looked wild and messy, but magical!
Tip: If you have lots of kids, and they’re keen to try this experiment, go ahead and buy a whole bag of potatoes. That’s the cheapest way to have fun with this activity.
I was amazed at everything my kids had learned from this simple experiment with everyday items.
Looking for more Dr. Seuss inspired science?
Are you looking for more Dr. Seuss-themed ideas?
I joined a fantastic team of bloggers to share imaginative activities for kids – from LEGO to dinosaurs, STAR WARS to fun with nature. All you need to do is gather a few household items and you can have dozens of creative activities each month.
This month we are bringing you exciting Dr. Seuss-themed activities. Check them out:
Dr. Seuss Activities for Favorite Dr. Seuss Books from As We Walk Along The Road
Seuss-inspired Crafts for Kids from That Kids Craft Site
The Art of Dr. Seuss from Table Life Blog
Truffula Trees Craft from The Gingerbread House
Introducing Measurement with The Foot Book from Homeschooling in Progress