The Lincoln High Dive!
This is science? You betcha. Part of Newton's first laws says, in general, that an object at rest will remain at rest unless acted upon by an outside force. The energy of your movement with the pencil was passed on to the hoop, making it fly out of the way quickly, but the hoop moved too fast, and there was not enough friction to affect the penny (at rest) on top of the hoop. The penny ended up above the film canister with nothing to hold it up. It was about then that gravity took over, and pulled the coin straight down into the waiting water. Yep, Issac Newton and Abraham Lincoln, together in the name of science...sort of.
The project above is a DEMONSTRATION. To make it a true experiment, you can try to answer these questions:
1. Does the size of the hoop affect the accuracy of the falling coin?
2. Does the shape of the object on the hoop affect the accuracy of the drop?
3. Is the coin affected by how fast you fling the hoop out of the way.