1. Pressure

2. P = F ÷ A: (P = pressure, F = force, A = area)
Pressure_: The force exerted on a surface divided by the total area over which the force is exerted (PSI or Pa)
P = F ÷ A: (P = pressure, F = force, A = area)
Ex: 100 lb ÷ 20 in2 = 5 PSI
Pascal (Pa): a unit of measure for pressure. Pa = 1N/m2
Bill Nye: Pressure
Mud shoes-4:20; vacuum-:16; water rocket-10:31; water pressure/dam-15:31; water jet-15:48

3. Air Pressure pushes equally in all directions.
At sea level it is 14.7 PSI
As elevation increases,
air pressure decreases.
Water pressure
increases with
increases in depth.
Mariana Trench: 7 miles down,
8 tons per square inch pressure

4. If air moves faster above the object, pressure pushes the object up.
Bernoulli’s Principle: The rule that a stream of fast-moving fluid exerts less pressure than the surrounding fluid.
If air moves faster above the object, pressure pushes the object up.
If air moves faster below the object, pressure pushes the object down.
The object always moves
toward the
low pressure
area.
How an airplane flies video

5. Bouyant Force (buoyancy): The upward force exerted by a fluid on an object
Bill Nye: Buoyancy
Archimedes-2:08
Float-8:00
Neut.Buoyancy-13:38

6. Density: The mass of a substance contained in a unit of volume (D=m/v)
(D = density, m = mass,
v = volume)
ex: 50g/5cm3 = 10g/cm3
10g/5ml = 2g/ml
density video clip

7. Archimedes’s Principle: The rule that the buoyant force on an object is equal to the weight of the fluid displaced by that object
Conceptual Physics: Demo of Archimedes' principle - YouTube

8. Pascal’s Principle: The rule that when force is applied to a confined fluid, the increase in pressure is transmitted equally to all parts of the fluid.
Hydraulics & Force Pumps: fluid is transmitted & multiplied on the other end.