Day 1: Cups and Pennies Lab
Students were given a penny, and index card, and a paper cup (6 oz.). Step one: Observe the penny. What is it doing? Nothing! Now, the challenge? Get the penny in the cup without touching the penny. Of course they figure out some way to do this, so next I have them set up the cup with the index card on top of cup... penny on top of the index card. Try again. (The trick I want them to get is to quickly pull out the index card so that the penny drops into the cup.) New rule- can't touch the card with your hands. (They will try their nose! ok... so no skin involved at all) Eventually someone will try their pen or pencil to hit the card out of the way.
Hmmm... so what is this all leading up to? INERTIA! Everything stays as is until a force is added. What force moves the card? (Your hand or later the pen/pencil) What force moves the penny? (Gravity) BUT, I don't tell them any of this yet!