Flattern out a magazine on the floor. Hand over six playing cards to a friend. Ask him to drop each card from a few feet height. So it lands on the magazines. Show him how to hold a card, as shown in the illustration, but don’t tell him that the card has to be held vertically before it is dropped. If he holds the card vertically before dropping it, it will flutter to one side, missing the magazines. Now you show him the way to do it. You hold the card horizontally, so that the card is parallel to the floor. Let it go. The card will land on the magazines.
HOW DOES IT WORK?
When a card is dropped, gravity pulls it towards the floor. The surrounding air , however, resists its downward fall. Dropped horizontally, it more...