Day 100: Drop a bullet. Shoot a bullet. Which hits first?
No need for fancy set-ups here. Just give the kids some ice-cream cone shooters and have them do the experiment themselves. You can get them at your local party store. We re-use them for several projectile investigations and a challenge to find the launch velocity of the toy using 2 different methods. (Similar to the popper, but now they must use 2-D projectile motion for one of the methods.)