Newton's First Law

Here's a quick, easy experiment that you can do with your kids that illustrates the concept of Newton's First Law.  Newton's First Law states that "an object in motion (or at rest) remains in motion (or at rest) until a net force acts on it."  In this experiment from Science Bob, we're trying to drop a penny into a small pill bottle, by yanking something out from underneath the penny.  This is very similar to the table cloth yank where you place wine glasses on a table cloth and yank the table cloth out from under the wine glasses without knocking the glasses over.  In this case, however, there is nothing to break, so much safer for kids.

As you can see from the video, we've placed a penny on a loop made out of card stock.  By yanking the loop away very quickly, the penny falls straight down.  Since the penny is at rest, it will stay at rest until a net force acts on it.  Since the card stock is yanked away quickly, there is little to no force acting on the penny, so the penny falls straight down.  Cool!