Objective 1 : Demonstrate that the pressure in the phase solid or fluid (liquid or gas) is different
Pressure is the result of a force applied on a given surface; because of their nature the surface of contact of the fluid (liquid or gas) will be different from that of the solid.
The results will be that the force that has to be considered in a fluid will not be the same for fluid than for liquid. Indeed if you put all the see in a reservoir and then you put your hand under the reservoir, the pressure on your hand is due to all the weight of the sea water. While if you put your hand in the sea water at a depth of 2m the pressure is that of the column of water above your hand. Let’s experiments this.
30 Minutes
What is the difference between the pressure between a solid and a liquid or a gas?
Note that the container should be light so that its weight is negligible compared to the weight of the water.
This experiment is a step between experiments of the pressure of solid and fluid. At this stage ask your students to express themselves and to react to these experiments.This can be done by drawing, writing or speaking.
During these experiments students should have felt pressure within a liquid and they have experimented that there is a difference between a pressure within a fluid and with the contact of a solid.