1. Do Now
A raft is made of a plastic block with a density of 650 kg/m3, and its dimensions are 2.00 m × 3.00 m × 5.00 m. What is the force of buoyancy on the raft in water?

2. SWBAT: Discover pressure and how to calculate it.

3. Homework!
Check you answers as I read them and ask questions if you are confused.

4. Notes! Pressure: Magnitude of the force on a surface per unit area.
P = F_ A
Pascal’s Principle: The Pressure applied to a fluid in a closed container is transmitted evenly to every point in the fluid and to the walls of the container.

5. Lab time!
Your goal is to determine how volume and depth effect the pressure on an object in a fluid.
Fill the beaker to 1000 ml and the graduated cylinder to just above the word ValueWare.
Take measurements every 200 ml of the beaker and every 5 ml on the cylinder.

6. DATA Depth Pressure in Cylinder Pressure in beaker Air Pressure 25/800
20/600
15/400
10/200
5/0
0/NA

7. Notes Pressure is measured in Pascals (Pa) = 1 N/m2
Atmospheric pressure is equal to 101,000 Pa

8. Notes!
P = P0 + ρgh
Where P is the total pressure, P0 is the atmospheric pressure, ρ is the density of the fluid, g is gravity and h is the depth below the surface.
ρgh is called the gauge pressure

9. Example
What was the pressure at the bottom of the cylinder? (Air pressure = 101 Kpa and the depth is 0.11 m)

10. Example 2
A penguin can endure pressures as great as 4.90  106 Pa. What is the maximum depth to which a penguin can dive in sea water? The density of sea water is  103 kg/m3

11. Example 3
In 1960, a bathyscaph descended 10,916 m below the ocean's surface. What was the pressure exerted on the bathyscaph at that depth?

12. Homework
Pg 283; 1 – 4