Last week in Science, Year 3 were learning about the difference between contact and non-contact forces. We brainstormed examples: contact forces such as a ball being kicked or a door being pushed and non contact forces such an apple falling from a tree or magnetism. We looked at magnets being used in every day life (e.g. on a building site and on a fridge door) and established that gravity is the invisible non-contact force that pulls everything in the Earth’s atmosphere to the centre of the Earth.
We then looked at a range of different magnets and discovered that they come in different shapes and sizes: we particularly focused on large horseshoe magnets, magnetic wands, bar magnets and small magnets like button and marble magnets. We decided to investigate which magnet was strongest. We unanimously predicted that the largest magnet would be the strongest but there was only one way to find out if we were right!
After writing up our investigation, we placed a paper clip next to a ruler laid out on the desk level with 0cm. We then held our magnets 30cm away from the paper clip. We kept edging the magnet closer to the paper clip until the clip was attracted by the magnet. At the point of attraction we recorded the distance the magnet was from the paper clip. We repeated the investigation for all the magnets and compared our results. It was important to keep the investigation fair by keeping the equipment and location the same each time. The only variable that changed each time was the type of magnet used.
