Newton's First Law and Balanced Forces

Take a penny, an index card and a plastic cup. Place the index card over the cup and place the penny on the index card. Now, flick your finger at the index card, striking it horizontally. What do you observe? Next, take a stack of five pennies. Can you think of a way to remove just the bottom penny from the pile without touching the stack with your hands?  Post your observations and your solution on the discussion board, and include a hypothesis for what you think is going on.

Make your initial post, then return to the discussion board several times over the next few days to read your classmates’ posts. Reply to at least two of them, being sure to offer new insights, ask questions, and encourage further conversation.