A Fun Unit On Catapults
A catapult is a device that flings or hurls an object a long distance, usually with great force. Catapults date back to around 399 BC and were primarily used for destroying or creating an opening in castle walls or the walls of fortified cities to allow the invading army to enter. At times, they were also used for hurling flaming missiles and other items over the castle or city walls.
In the free catapult unit study on this page, I've included several lessons and activities about building, experimenting with, and understanding levers and catapults. A short history of catapults and a brief description of the major categories of catapults are also provided. If you are interested in purchasing a catapult kit, or trying your hand at building a catapult model with materials you have around the house, you'll find some recommended models below!
I hope you find this page interesting, and have fun making some catapults of your own!
Catapult Unit Activities
Catapult related activities covering a variety of subject areas
Most of the following catapult activities could be done in either a homeschool co-op setting, a regular classroom, or at home. My son and I did some of these in our homeschool co-op, some at a park with a friend, and others at home.
Feel free to pick and choose those lessons and activities that meet the needs of you or your children. It certainly isn't necessary to do them all!
Lesson 1: Simple Machines
Understanding how catapults work! Most catapults have levers, and a lever is a simple machine!
Simple machines help us do work by magnifying or changing the direction of a force.
Here are the 6 simple machines.
3. Inclined Plane
4. Wheel and Axle
6. Screw (which is really a type of inclined plane!)
MiKids.com's Lesson on Simple Machines gives a good description of the six types of simple machines and also provides plenty of photos! (Visit the links under "Activity" on that page to find the photos!)
Introduce the child or children to the different types of simple machines, discussing the use of each one. Next give the child(ren) some simple machines (screwdriver, tongs, etc.), or photos of simple machines, and have them sort them, putting the levers in one pile, the inclined planes in another, and so on.
As an alternate activity, allow the child(ren) to walk around and find simple machines and identify them for you! If they are having trouble trying to find a certain type of simple machine, give them some hints.
Lesson 2A: Exploring Levers
A Physical Science Lesson
Provide the student(s) with a variety of tools to use, such as rulers, yard sticks, plastic spoons, pencils, and fun noodles (the kind that you play with in the pool), and asked them to select one to use. Next give each student a marshmallow, asking them not to eat them! Place a box on the floor a few feet away, and instruct the kids to try to use their tools to fling their marshmallows into the box. Here's the rule: One end of their tool must remain on the table at all times. It isn't necessary to use the word, "Levers" with the students yet. Simply let them explore what their "tool" can do.
After trying it a few times, you may wish to allow them to trade tools and try again. Finish the lesson by allowing the children to discuss which tools and techniques worked the best, and why.
The kids in our homeschool co-op had such fun with this activity!
Lesson 2B: A giant balance board is a great way to experience the power of a lever first hand!
While having fun on this large balance board, we talked about the fulcrum and experienced first hand what a lever was like!
On this large lever, we did various experiments, such as exploring where everyone needed to stand to balance the board if you had two people on one side, and one on the other. What happens if there are four people on one side, and one slowly walks up the ramp towards the other side? What if everyone starts in the middle, and one person walks to one side? What if everyone starts on one end, and one by one they walk toward the other side? When will the board be balanced? When will the board tip?
Granted, most people won't have access to a large balance board like this one, but you might be able to explore the same concepts by sitting at different places on a seesaw (be careful where you sit so you don't get pinched or hurt).
Lesson 3: Creating a miniature working catapult ....without directions!
Critical Thinking, Art, and Physics Lessons All Rolled Into One!
Too often, we give information to children and expect them just to memorize it. We often forget to encourage them to think for themselves! In our homeschool co-op, I teach a class on critical thinking for middle schoolers and high schoolers. Every week I give them challenges to complete without directions! The youth often work together in teams of two or three, in order to learn team work and communication as well. After all, as adults, won't most of them have to work with others? Together they plan how they will complete the challenge, and then they set out to do it. Sometimes they have to revise their plans as they go, but that's all part of the learning!
The lesson below is one we did in our critical thinking class. The students absolutely loved it!! And I honestly did not have to give them any directions at all as to how to make their catapults! I love watching them in action and observing how very creative and intelligent these youth really are!
Here a team of two is creating a catapult via their own plans.
(We did this lesson on Halloween, so one of the boys is wearing his Ninja costume!)
This activity can be done individually, or in groups of two to three. It is probably more fun, as well as more educational, if there are at least two catapults built (although they can be built by the same person, or mom or dad can join the fun, if you don't have other children to participate in the activity).
Gather a variety of materials (drinking straws, rulers, plastic spoons, rubber bands, string, popsicle sticks, small paper cups, a roll of masking tape per team, paper clips, a few index cards, scissors, etc., plus marshmallows as the rocks). Each student or team will make and test their own catapult.
Hint: When I do activities of this nature at our homeschool co-op, I like to prepare gallon size ziplock bags in advance with all the supplies each team needs. That way you can simply hand each team a bag, and won't have to waste class time dividing up the supplies!
Since this is a lesson in critical thinking, don't give the kids instructions as to how to build their catapults. Allow them to come up with their own plans!
I recommend giving them about 20 to 30 minutes to design, and redesign if necessary, their catapults. Allow them to use as many or as few of the materials that you've provided as they'd like. Each catapult should be unique! When time is up, allow them to to launch their catapults, one by one. Perhaps each team should get three tries?
Which catapult can shoot their marshmallow the farthest? What is it about that catapult that seems to make it so effective?
If you place a box on the floor, can any of the catapults make a "hole in one" with their marshmallow? Which catapult seems to have the best aim? Why?
Here's one of the kid-designed models that a team of three youth in our homeschool co-op made.
In doing this lesson, kids will gain a better understanding of the workings of catapults, and will learn critical thinking and teamwork skills (by coming up with their design and working together), and physics (experimenting with what needs to be changed in order to get the marshmallow to fly farther). Plus, each catapult will be a piece of art!
Lesson 4: Building A Catapult Model From A Kit - And doing experiments with it!
Although making your own catapult without any directions (in the lesson above) is a wonderful introduction to catapults, a sturdier, more professional catapult will allow you to do further experimenting. There are many kits available for building a catapult. The one we purchased came with everything needed to make a catapult, including small blocks of wood, wood glue, written directions, a few other small items, and soft bags to launch once you got the catapult built. We built the catapult in about an hour and then allowed it to dry overnight. (The instructions said to allow it to dry 12 hours.)
Using the catapult for experiments and activities:
The next day the whole family got involved in experimenting with the catapult.
1. We tried a variety of objects as the missiles (cotton balls, marshmallows, rubber balls of different sizes and weights, etc), guessing which one would go the farthest, and then experimenting to find out.
2. The kit came with plenty of extra blocks of wood, so we experimented with adding more wooden blocks at the base to force the lever arm to stop sooner, in order to find out what angle worked the best for our catapult.
Did 5 blocks (which causes the lever arm to stop sooner) have a different outcome than one block (which allowed the lever arm to go all the way up)? Did increasing the number to 8 blocks change things even more?
3. The catapult kit came with a target to place on the floor, and we had lots of fun trying to get our beanbags (that came with the kit) to land on the target after being shot from the catapult. We also tried to get small rubber balls (that we already had on hand) that were shot from the catapult to knock down wooden blocks (included with the kit) we'd set up like dominoes!
An Excellent Catapult Kit! - This is the catapult kit we purchased and used for our experiments.
This is the kit we purchased, built, and used for our experiments. It worked out well! The catapult is sturdy and was fairly easy to make! Elementary aged kids will likely need some help, but middle school and high schoolers can probably build the kit with very little help. (At times it was helpful to have one person hold the wood while another glued it.)
By the way, I noticed a customer review on Amazon about it taking four days to build the kit. That really isn't necessary. My son built it in about an hour, and then allowed the glue to dry overnight. We didn't find it to be necessary to let the glue dry overnight BETWEEN each step...only at the end. After completing one section that needed gluing, he put it aside while working on the next section. By the time the second section was done, the first was sufficiently dry. This was our results, and of course yours may differ....but we had no problems whatsoever, and found this kit to be superb!
More Catapult Kits
Amazon has quite a few catapult kits for sale. Here are four of them. I don't have any experience with the four listed here, as the one we bought is the one mentioned above. If I were to buy another kit, it'd probably be one of the Trebuchet kits, simply because that's a different kind than the others we've built so far.
Miniature Ballista Kit - The Ultimate Roman Artillery Weapon
Contraptions Trebuchet - This catapult was made by the same company that made the catapult we purchased and used.
You can change the hurl of the Contraptions Trebuchet by altering the counterweight. Experiment to see how you can change the distance the ball travels, and then try to use your trebuchet to knock down small planks (included) with the launched balls.
Lesson 5: Learn About The History and Types of Catapults
Pitched Battles and Sieges
In ancient times, regions often invaded other regions in order to acquire their land or wealth. Everyone wanted what someone else had! Soldiers used pitched battles and sieges to conquer others and take their resources.
Pitched battles took place on a battlefield and involved hand to hand combat, skirmishes (small battles), and frontal assaults. A variety of weapons were used in these battles, such as daggers, battle-axes, bows and arrows, clubs, and spears.
Sieges, on the other hand, took place when one army was behind the walls of a castle, fortress, or walled city. Different techniques were used to conquer the castle. In a blockade, the invading army surrounded the castle to stop supplies from getting in. Sometimes, though, those within the castle had more supplies than the invading army and could thus hold out for longer! Other times, threats or bribes were used in an attempt to get the other side to surrender. Spies were used sometimes as well.
If these methods didn't work, the invading army might be forced to attack the castle itself. This was no easy task, as the stone walls of the castle were several feet thick! One strategy for conquering the castle was digging tunnels under the castle wall. Another strategy involved removing enough dirt from under the wall to cause it to collapse. Obviously, both of these methods took quite some time! Yet another method made use of tall movable towers. The towers, with ladders inside, would be rolled up to the wall and a bridge would then be lowered down the other side. The soldiers could then easily and quickly climb the tower, cross over the wall, and run down the bridge!
Other techniques for conquering a castle involved blasting the castle wall with various types of missiles! That's where catapults came in!
The first catapults looked quite similar to large crossbows, and used much of the same technology.
The earliest catapults, dating back to around 399 BCE, were tension catapults. Tension catapults shot heavy darts (called bolts) and worked by bending back a bow that was usually made of animal horn or wood. Although they were powerful, their disadvantages included the time it took to load and fire them, as well as their large and heavy size.
Around 340 BCE, torsion catapults came into use. Torsion catapults used springs made from coils of rope as their power. Some types also had throwing arms on either side of the catapult. Ballistas, Mangonels, and Onagers are all types of torsion catapults.
As the winch is turned on this torsion catapult, the bowstring is pulled back, which pulls back the throwing arms, thus tightening the ropes. When a pin is pulled out, the ropes are released, and the bolt is shot forward.
Gravity Catapults (Trebuchet)
Gravity catapults, such as the trebuchet, first began to be used by the Chinese armies around 600 to 900 CE, but didn't enter widespread usage until around 1200 CE. In gravity catapults heavy weights were attached to one end of a lever arm. When the weights fell, the other end of the lever swung quickly up, throwing a rock or other item(s) in a high arc toward the castle wall.
In this drawing of a trebuchet, a sling is currently holding the rock or other ammunition in a raised position. The side of the arm with the sling on it will be pulled down, raising the weight on the other end of the arm. When the weight is dropped, the sling side of the arm will fly up in an arc, releasing the contents of the sling and hurling them through the air.
Around 800 CE, traction catapults became popular. These catapults were more like our idea of a catapult today in that they had levers which were pulled down and then released to shoot rocks long distances.
Compared to the stones (which could be 200 pounds or more!) thrown by the onagers, trebuchets, or mangonels, these Ballista bolts were relatively light weight!
Catapult Use During WWI
During World War I, hand grenades were launched across "no man's land" into the trenches of the enemies via catapults.
Did you know that catapults are also sometimes used to launch aircraft?
In this photograph, taken in 1943, an amphibian aircraft has just been launched from a catapult on board the HMS Bermuda.
*Please note that this is not meant to be a complete and detailed account of war techniques and weapons during ancient and modern times. Whole books have been written on the subject. This section is meant to be just a brief overview. For more info, please read a good book on catapults, such as The Art of the Catapult, or visit one or more of the following websites.
The History and Types of Catapults - More information about catapults and their history
- Catapult History and Modern Day Construction
This website includes a description of the various types of catapults. It also includes a couple of models that can be built by kids.
- What the Ancients Knew: The Roman Catapult
This is a fantastic video of a Roman ballista being made and shot.
This website is about the history and design of the Ballista.
- The History of Catapults
This interesting website explains how catapults evolved from crossbows!
- Wikipedia Article on Catapults
This article provides pictures and information about the history of catapults.
- Aircraft Catapults
This Wikipedia site has lots of information and photographs of aircraft catapults.
Catapult: A History - Interested in finding out more about the history of catapults?
Would you rather learn about catapults or learn with catapults?
Books About Catapults - The Art Of The Catapult
Greek and Roman Siege Machinery 399 BC-AD 363
What Brings You To My Article On Catapults?
Lesson 6: Learn about different types of catapults by building small replicas
The directions for these small catapults are all available for free online.
To make the "Teeny Tiny catapult," you'll need:
10 popsicle sticks, a ruler, a long rubber band, a pencil, a roll of masking tape, and scissors.
2. Build a Ballista Catapult.
A Ballista catapult is a Greek catapult which has two vertical torsion springs (the 2 vertical white ropes on this one).
Pictured here are two different views of the Ballista Catapult we made.
Ballista catapults have a bowstring and throwing arms, and shoot darts, rather than rocks.
To make this Ballista Catapult model, you'll need:
a glue gun and glue sticks
a ruler or measuring tape
For the dart, we rolled a piece of paper and then taped it closed.
3. Build an Onager Catapult
Onager catapults use twisted rope to create the force that propels the lever arm forward. Onagers were a type of torsion catapult.
To make this Onager catapult, you'll need popsicle sticks, string, a hot glue gun and glue sticks, a piece of paper, tape, and scissors.
Note: Although it's not as authentic, if you can't get the twisted string to provide enough force, you may wish to wrap a rubber band around the base and twist that instead.
Are you an experienced catapult builder?
Another Working Catapult Model - This one can be made in just a few minutes!
A wire hanger
a plastic spoon
two rubber bands
Just follow the easy direction on the youtube and you'll have your catapult ready to fire in five minutes or less! At the end of the youtube, experiments are suggested for ways you can improve your catapult. Also, a brief lesson on levers is given.
Stomp Rockets, Catapults, and Kaleidoscopes! - 30+ Amazing Science Projects You Can Build for Less than $1
Backyard Ballistics: Build Potato Cannons, Paper Match Rockets, Cincinnati Fire Kites, Tennis Ball Mortars, and More - Build a tabletop catapult, a spud gun, an
Mini Weapons of Mass Destruction: Build Implements of Spitball Warfare - Want to make a clothespin catapult? How about a siege or viking catapult?
Step by step directions are included in this book for creating 35 devices, some of which are slingshots, darts, catapults, minibombs, and combustion shooters.There's a tiny trebuchet you can make with a D-cell battery and paper clips. A small "bomb" you make with a penny and some other things. There's a coin shooter, a simple crossbow, a bow and arrow pen, a water bomb, a matchbox bomb, a clothespin catapult, a siege catapult, a viking catapult, ping pong zooka, and a whole lot more! Optional directions are provided for some of the projects for attaching a laser pointer sight to your device, in order to help improve it's accuracy!
Using homemade catapults to shoot marshmallows at a castle.
These are some of the kids in our homeschool co-op having lots of fun while learning too!
What about an extra large homemade catapult? - This was designed and built by some high school students.
My daughter and some of her high school friends created this large catapult. It involved a great deal of experimenting and redesigning, but they learned a lot from it! They did the entire thing alone, from planning to sawing (with adult supervision) to assembling to testing and redesigning and testing and redesigning, and...well, you get the idea! Their projectile was a tennis ball.