Pressure is not just a kind of force
Teaching Guidance
for 11-14
Pressure vs. force
Wrong Track: The pressure of the water pushes directly on my ear drums.
Right Lines: The pressure of the water gives rise to a force which acts over the exposed area of my ear drums.
Pressure and forces are distinct
Thinking about the learning
Pressure and force are two distinct kinds of things. The words tend to be used interchangeably in everyday contexts but in science they have quite specific and different meanings.
Thinking about the teaching
Aim to develop the picture of pressure as existing throughout a fluid and giving rise to forces in all directions due to the bombardment of the fluid molecules. Forces act on objects in particular directions; a pressure simply exists throughout a fluid.
