How can you balance a seesaw?

The swing can stand upright

The earth pulls the cubes down. The cubes press on different ends of the swing. Everyone tries to tilt their side.

Let's place identical cubes equally far from the middle. They tilt the swing equally hard. Neither side outweighs.

Imagine two identical children on the edges of a swing. If they sit equally far from the middle, the swing can stand level.

The heavy side goes down

Let's put a heavier cube on the right. The earth pulls him harder, and he presses harder on his end of the swing.

Both cubes are still equally far from the middle. Therefore, the heavy side outweighs and falls.

The other end rises with the board. Now let's try to help the light cube. A heavy cube can be moved.

Distance is also important

Let's move the heavy cube closer to the middle. He has not become lighter, but now he tilts the swing more weakly.

It's like a door: it's easier to turn it by the handle than by pushing it near the hinges. The push is stronger further from the turning point.

Our red cube weighs the same as two yellow ones. Let's put it twice as close to the middle as the yellow one. The swing is level again!