Making snowball catapults

The chances of it being a white Christmas this year are as slim as ever so why not bring a snowball competition into the classroom with this fun activity? Challenge your class to build the best catapult which is capable of launching a ‘snowball’ (a white marshmallow) as far as possible and see whose engineering skills are the best.

Supply the class with a number of different materials that they could use to build their catapult. Suitable examples include: lollypop sticks, plastic spoons, elastic bands, toilet rolls, straws and cardboard boxes. They will also need scissors and plenty of tape. Split them into teams and ask them to use the internet to looks for design inspiration as well as top tips on catapult construction.

You can provide the teams with some things to think about:

• The launching mechanism will need to transfer energy to the snowball. What type of material/structure stores energy? (elastic/springs)
• The snowball will go the furthest if it released at a 45 degree angle – how can you measure this? (a protractor or set square)
• The base of the catapult needs to be strong so it doesn’t collapse when you launch the snowballs. Which shape is the strongest? (triangle)

Then, each team should be given a large sheet of paper on which they can talk through their ideas and draw out their design before building it. Ask teams to test out their catapult and allow time for further modifications before competing against each other to see who can launch their ‘snowball’ the furthest. The winning team could win a bag of marshmallows to share.

Ideas to expand the activity

Ask the groups to apply their knowledge about energy and forces to explain how their catapult works.

Ask them to build an accurate and precise catapult. An accurate catapult will hit the target, a precise catapult will hit the same area each time. This is a nice opportunity to discuss the difference between these two words using the dartboard analogy.

When it comes to the final competition, set up cardboard targets of different sizes and place them at different distances. Give each a point score depending on how small it is and how far it is from the launch area. Then give each team five ‘snowballs’ and see how many points they can score by knocking down targets.

Another Christmas themed Working Scientifically activity is explained in Christmas Science – The science of Christmas.

By Gemma Young for Smart Learning