1. Pressure
Chapter 3.3

3. Pressure Pressure = Force ÷ Area P = F Force: Newtons (N)
Pressure: A measure of how much force is acting on a certain area
Pressure depends on Force and Area
Pressure = Force ÷ Area
P = F Force: Newtons (N)
A Area: square meters (m2)
Pressure: Pascal (Pa)

4. Think about it… Why are snowshoes so helpful for walking in snow?
The force (person’s weight) is the same but it is spread out over a large surface area.. Therefore, less pressure is exerted on the ground and you don’t sink in the snow!

5. Pressure in Fluids Particles in a fluid are moving in all directions
As they collide with an object, they apply a constant force which produces pressure
The pressure in a fluid is exerted in all directions

6. Think about it…
What happens as you climb a high mountain? Does air pressure increase or decrease?

7. Pressure in Air
Air exerts a pressure on you at all times: Atmospheric Pressure
Changing Elevation: as you increase elevation (climb a mountain), air pressure decreases. There is less air above you pushing down.
Changing Density: Air at lower elevations is denser, higher pressure
Video

8. Think about it…
What happens as you dive deeper into a pool? Does the pressure increase or decrease?

9. Pressure of Water The deeper you swim, the more water is above you.
Water pressure increases with greater depth.
Water exerts more pressure on you than air because water is more dense
If you were to dive 1,000 meters into the ocean, the pressure would be 100x greater than air pressure.