Experiment about the force of water

 

Preparatory activities:

 First, we needed to prepare of the following necessary materials:

- a basin of water

- a piece of cardboard

-scissors

-liquid soap

Activities:

The students filled a basin with water. From a piece of cardboard, a child cut a triangle, which was placed in a corner of the basin with one of the points pointing towards the center.

A student put a drop of soap on the tip of a finger (this operation was performed near the basin) and then inserted the finger into the water, behind the cardboard triangle.

The surprise consisted in quickly removing the piece of cardboard (the boat) from next to the child's finger, in the opposite direction.

The soap mixing with the water decreases the force of attraction between its molecules, making it possible to remove the dirt (in our case the boat) from the finger with liquid soap.

 Subsequent activities:

Free discussions based on the experiment, taking as an example the phenomenon of removing dirt from dishes / laundry, at the moment of introducing the liquid detergent.

 Results:

Student were satisfied by the result and the practical implementation of some theoretical information.