Newton's First Law of Motion...Quick Demo

Newton's First Law of Motion states that: "An object in motion stays in motion and an object at rest stays at rest unless acted upon by an unbalanced force."

That ball bearing in the video wants to remain in place (it has what is called "inertia") but only if you can overcome the force of friction between the ball and the playing card.

If you move the card slowly, you don't overcome the force of friction and the ball moves with the card.

The same thing happens when you pull a sheet of paper out from under a book. Or even a tablecloth from under a place setting... Don't try that at home!

Have any other demonstrations that apply to this principle?