1.This is the way the inside of a toilet tank looks as you flush it.
It is full of water.
When you push down on the handle, it pulls up a wire inside the tank. The wire pulls up a stopper that blocks the pipe linked to the toilet bowl. The water in the tank goes down into the bowl. As the water goes out of the tank, a hollow ball called a float will rise with it. A long stick on the float is connected to a plug in the water pipe. The float goes down far enough to lift the end of the stick and pull the plug. Fresh water comes through the water pipe into the tank.
2.Which of the two parallel line segments on the left is longer?
Measure them with your ruler. Were you right?
If not, why might you have been wrong? The sketch is an example of an optical illusion-a visually perceived image that is deceptive. In the exanple, the segments on the sides move toward each other as they extend downward, giving the illusion that segment A B is longer than segment C D. Optical illusions can trick you into seeing something that is misleading or false. While there are many kinds of optical illusions, the one in this activity is created with parallel lines. The lines that are not parallel distort the distance from A to B and C to D.