Rollback Can
Materials:
• Coffee tin
• Nail
• 9 volt battery (or something with the same weight)
• Thick rubber band
• 2 paperclips
• Sticky Tape
Procedure:
1. Make a hole in the middle of the bottom of your coffee tin using the nail.
2. Poke the same kind of hole in the lid of the can.
3. Tape the 9-volt battery to the middle of the rubber band.
4. Make sure both sides of the rubber band are taped to the bottom of the battery.
5. Push one end of your rubber band loop through the hole in the bottom of the can.
6. Secure it there by attaching one of the paperclips.
7. Tape the paperclip down.
8. Stretch the rubber band across the length of the can and push the other end of the rubber band loop through the hole in the lid.
9. Secure the lid with a paperclip and tape it down.
10. Put the lid on the can.
11. Set the can on its side on a hard surface or short carpet floor and give it a roll.
12. Watch it come back to you.