5 Minute STEM Activity 9: Spoon Catapults

Cavemen probably played with miniature catapults as children, the technology is incredibly old. They are very simple to make and this is one of the simplest. It is a great way to use energy and motion to create different types of energy and motion. Mechanics, powered by your finger...

Spoon Catapult
Fantastically Flingy

EQUIPMENT:
Small collectible toys, rubber are best*. The type that come in blind bags and don't cost more than 50p each - then your mum won't be mad you won't be sad if you do temporarily lose any (don't use your favourites).
Dessert or soup spoon
Plastic water bottle, half full of water with the lid on tightly or cardboard tubes (kitchen roll or crisp tubes).
Sticky tape
Plastic bowls or similar for targets

*Small objects to fling - if you don't have any small collectible toys or yours are too precious to risk losing, you can use tightly crunched up paper. There are other rules:
a. Your objects cannot be metal or glass, or feel heavy or hard like metal or glass - e.g. dice.
b. Your objects cannot have sharp edges, points or corners.
c. Never aim towards animals or people, and watch out for your cat/baby brother getting into the way.
d. Your objects must not be bigger than the spoon, if they overlap the edges, they're too big.

1. Lay the water bottle (or cardboard tube down) and rest the spoon against it, with the bowl end of the spoon on the ground.

2. Find the middle of the spoon and tape it to the middle of the bottle or tube. You don't have to measure exactly.

3. Find a quiet and clear spot to work in. You need a space about 1 metre by 2 metres (3ft x 6ft) and you need a safe space behind your targets, to catch any misses. A blank wall is best, or a closed door. Don't fire towards things like hedges or kitchens or bookcases because you will lose your toys until you have had a bit of practise. Upstairs hallways can be good places, but check you won't be in anyone's way.

4. Put an object into the bowl end of the spoon

5. Hit the spoon handle - this will not be skillful.

6. Practise until you can get your object into a bowl a few times, at different distances up to 2 metres (6ft) away. This is more skilled. You need to do lots of mental maths in order to get a direct hit, although you may not even realise it. Your brain has to calculate and estimate speed, height and distance of your toy, and direction, power and speed of hit to fling the toy into the bowl.

7. Try using more bowls, you can give each different scores for direct hits and try to beat your own score, or play against a friend.

You'll find that by varying your speed of hit, and how long your hand stays in contact with the spoon, you can control the height and distance of your shot. The toy will make an arc shape as it flies, rising and then falling. The angles of up and down will depend entirely on how you hit the spoon

If you cannot balance your figures on the spoon, try putting a book under the bowl end of the spoon to raise it a little bit.

The study of the relationships between motion and forces is called mechanics, and you'll be familiar with that term because it is a mechanic who fixes a car. Mechanics isn't just about vehicles though, it's about how everything moves, including people and bits of people. Even your little toe.

We found that the water bottle was much better than the crisp tube. Why do you think that might be? Size? Weight? The amount of leverage?

 You can find my other 5 Minute STEM Activities here:
Fish In The Tank
The Floating Arm Trick
The 5cm World Challenge
What Is Gluten?
How To Step Through A Hole In A Postcard
Turn Black To White
Is it Warm Or Is It Cold?

The Banger