Transcript PowerPoint

Day 1
Fluids
Particles are free to
move past each other
Gases and liquids
Why do things feel
lighter when they
are under water?
Buoyant Force
Upward force on
submerged objects
Opposite gravity
Lower Pressure
Higher Pressure
Pressure differences create FB
Sink or Float?
Depends on the net
force
Archimedes
Principle
FB = weight of fluid
displaced
Method 1:
In formula form:
FB = Vg
Method 2:
FB = Actual weight – Apparent
weight
Method 3:
For floating objects:
FB = weight of object
Practice Problems
Archimedes’ Principle Lab
Day 2
To Find FB for your
boat…
1. FB = Fg
• 2. FB = Vg
•
Imagine…driving in the
mountains or flying in an
airplane…what happens to
your ears?
Pressure
Force per unit area
P = F/A
Pascal (Pa) = N/m2
Or atmosphere (atm)
At sea level…
Air pressure is 1.01 x
105 Pascals
1 atmosphere
Pressure Problems
#1
Pascal’s Principle
Pressure is equally
transmitted to all parts
of the fluid and the
container
Think toothpaste…
Pascal’s Principle
Hydraulic systems
P1 = P2
Example
Pressure Problems
#4
Pressure varies with…
Depth
Density
Gravity
P = gh
Calculating Absolute
(or Total) Pressure
P = P0 + gh
Pressure
Problem #6
Pressure Lab
Day 3
Magic Paper
Hold a piece of notebook
paper just under your lower
lip and blow across it.
What do you observe?
Bernoulli’s Principle
The pressure in a fluid
decreases as the fluid’s
velocity increases.
Why?
PE + KE + P = PE + KE +P
(Law of Conservation of Energy)
Animation
Airplane
wings
generate
lift
because…