Balance is the equalization of a push or pull force where the mass of an object or force on an object equals the mass or force counting the object. Gravity is a force that pulls down on everything here on earth.
Things fall because of unequal mass distribution over a balance point. This happens because more of an objects mass such as the coins is on one side of the bill then on the other side. The law of attraction says that the more mass you have the more gravitational attraction you will create. This means that gravity will pull slightly harder on that side of the coin then it does on the other side of the coin crating an unbalanced force causing the coin to fall to that side.
Some people choose coins to balance it , some times it became artistic work like pictures i picked to you, so enjoy it and share withe you friends.
Hello, my name is Jack Sparrow. I'm a 50 year old self-employed Pirate from the Caribbean.