 It's going to rotate this way, rotate the water way. Can you see the duck is going up? When it rotates the other way, the duck goes down. When there's falling water on it, and when I'm rotating. The wheel and the axle rotates, that causes the duck. Now this is a simple task where we are making the duck go up and down. Similarly this force of water turns the wheel and axle. This can be connected to crush wood to make paper. In mills it can be used. We can make this with lot of force.