Watch the lesson presentation video and think about how gear, levers and pulleys are used in everyday machines. Look at the design by Rube Goldberg and start to think about designing your own cracking contraption. Watch the video below for further inspiration.
Then design your own cracking contraption in the style of Rube Goldberg ensuring you include gears, pulleys and levers as appropriate.
Use either the plain paper in your packs or the painting tool on PurpleMash.
Remember to label and annotate your design.