Paper Helicopter Drop Timing

None required — paper, scissors and a stopwatch only.

Disposal: Ordinary paper waste; recycle if your local recycling accepts paper.

Materials

• A strip of paper roughly 5cm x 15cm
• Scissors
• A paperclip
• A stopwatch or phone timer

Steps

1. Cut two slits partway down one end of the paper strip to form two 'rotor' blades, leaving a solid 'body' below them.
2. Fold the two blades in opposite directions so they stick out flat, like a propeller.
3. Fold the bottom of the body up twice and attach the paperclip to weight it.
4. Drop the helicopter from a fixed height (e.g. from a chair, always the same height for a fair comparison) and time how long it takes to land.
5. Try changing the blade length or the number of paperclips, and time each drop again.