Air pressure forces the cans to roll toward each other. The position and motion of objects can be changed by pushing or pulling.
Energy is a property of many substances and is associated with mechanical motion.
Above Standards from the National Science Education Standards . However, practice this activity before presenting it to your students. For the best results, the activity should be presented on a smooth and level table top. Place 23 straws on the table parallel to each other, about 1 cm apart. Place the cans upright on the rank of straws.