Is it true that lighter objects always fall slower than heavier objects? Start by dropping two balls at the same time and observe the landing. Did they move as you expected?
Dropping different objects and comparing their motion works well in the classroom - but doing it from a climbing net or the top of a slide may create more long-lasting memories, while emphasizing that physics works also outside the physics classroom. The photo shows preschool teachers comparing different pairs of falling objects and checking whether the orientation of sticks influences the time needed to reach the ground.
Read more about investigations of falling objects in a classroom, where students also compared lighter objects, investigating air resistance.
A falling slinky
A follow-up investigation can be to observe the motion of slinky dropped form a high point, e.g. a climbing rack or climbing net. The classroom discussion can consider forces on one of the coils of the slinky.