In science we are studying "Forces." We have looked at gravity, Friction and most recently air-resistance.
Firstly we made simple helicopter spinners and compared the time it took to fall to the ground with the size of the blades. We deduce: "The longer the blades the slower the time to reach the floor."
Then we made plastic parachutes and (tried) the experiment outside - however it was very windy and the results weren't as accurate. But from the ones that worked again we saw: The larger the parachute (surface area) the slower the fall.