Wednesday, November 11, 2009

AGENDA:

• Go over 8.5 Notes
• Work on Ch. 8 Review in class

ASSIGNMENT:

• Ch. 8 Review due tomorrow
• Ch. 8 online quiz for extra credit
• CH. 8 Test Friday

Thursday, November 12, 2009

AGENDA:

• Ch. 8 Review due today
• Go over and self-correct Ch. 8 Review

ASSIGNMENT:

• Study for Ch. 8 Test
• Last chance to take the Ch. 8 online quiz for extra credit
• Tomorrow is the last day for any make up work for Ch. 8

Friday, November 13, 2009

AGENDA:

• Remove notes from your binder to use on the test
• Turn in your binder
• Ch. 8 Test with notes

ASSIGNMENT:

• Have a fun and safe weekend!
• Go WJ wrestlers!
• We will begin Science Fair Project work in class next week
• Think if there is an adult (knowledgeable in the field of your "Going Green" project) whom you would like to have as a mentor through your project. If not, I will work to connect you with someone (professional in our community).
• You may have to collect data at home, but all project work will be done at school.

Tuesday, November 10, 2009

AGENDA:

• Go over Lab Quiz
• Begin talking about 8.5 Notes
• 10 minutes class time to work on review

ASSIGNMENT:

• Work on Ch.8 Reivew (See Monday's Blog.)
• Study and retake any Ch. 8 Quizzes this week to bring low scores up to 70%!

Monday, November 9, 2009

AGENDA:

• 8.5 notes (due tomorrow)
• 8.1 Reinforcement (due tomorrow)
• Work on Ch.8 Review (due Thursday)

ASSIGNMENT:

• 8.1 Reinforcement (due tomorrow)
• 8.5 notes (due tomorrow)
• Ch.8 Reivew (due Thursday)
• RV#1-10
• CC#1-10
• UC#11,13,14,15
• TC#16-20 (try 20!)
• DS#21,22,24,25

8.5 Uses of Fluids (pp234 - 239)

8.5 Uses of Fluids (pp 234 – 239)

SCIENCE WORDS:

• buoyant force – ability of a fluid to exert an upward force on an object immersed in the fluid.
• Archimedes principle – the Greek mathematician Archimedes stated that the buoyant force on an immersed object, is equal to the weight of the fluid the object displaces.
• Pascal’s principle – French scientist, Blaise Pascal, stated that pressure applied to the fluid is transmitted unchanged throughout the fluid.
• Bernoulli’s principle – the Swiss scientist, Daniel Bernoulli, stated that as the velocity of a fluid increases, the pressure exerted by the fluid decreases.
• Venturi effect – reduction in pressure of a fluid, resulting from the speed of the fluid, increases, as fluids are forced to flow faster through narrow spaces.

OBJECTIVES:

• State Archimedes’ principle and predict whether an object will sink or float in water.
• State Pascal’s principle and describe the operation of a machine that uses Pascal’s principle.
• State Bernoulli’s principle and describe a way that Bernoulli’s principle is applied.

NOTES:

I. Archimedes’ Principle

• buoyancy force is equal to the weight of the object displaced
• buoyancy an upward force in a fluid (gravity is downward)
• force is a vector quantity meaning it has size and direction
• if the buoyancy force is less than the object's weight, the object will sink
• if the buoyancy force is equal to the object's weight, the object will float
• if the buoyancy force is greater than the object's weight, the object will accelerate upwards

a. How do ships float?

• a ship will float if it's hull displaces water that weighs the amount of the ship's weight (to the water line it wants to have)
• denser water (marine water) weights more than fresh water, so less water needs to be displaced. (ocean ships would ride lower and may sink in fresher water, because they may not displace enough water to match their weight!) Edmond Fitzgerald?
• whether an object floats or not depends on its density
• objects with higher density than 1g/cm3 will sink unless it is fashioned into a shape that displaces enough water whose weight matches the dense material's weight.

II. Pascal’s Principle

• any pressure on a fluid is transmitted unchanged throughout the fluid
• water pressure is determined by depth and not the size of the body of water (just as altitude is what determines the atmospheric pressure)
  
  a. Applying the Principle (see the piston diagram on p 236)
• hydraulic machines use Pascal's principle
• a small cylinder and a large cylinder are connected by a pipe
• pressure is force/area
• so even though the areas of the two cylinders may be different, the pressure remains equal (pascal's principle) so the force can be magnified! (the same thing can happen in reverse for medical equipment that is working with very delicate tissues)
• Draw a picture of a piston showing equal pressure but unequal forces. (show the math!)

III. Bernoulli’s Principle

• as the velocity of a fluid increases, the force it exerts decreases
• velocity is also a vector quantity, as velocity describes speed and direction
• Bernoulli's principle describes how wings create lift (another upward fluid force)
• a wing is constructed so that air must travel faster over the wing than the air traveling under the wing. The slower air under the wing creates lift on the wing, an upward force.
• Draw diagrams of some other examples of Bernoulli's principle in everyday life: (label where pressure is high H and pressure is low L )

(if you print this out, leave more space for your diagrams here)

a. Windy Cities

• venturi effect - fluid flows faster when its forced through narrow spaces
• this increase in speed causes a reduction in pressure of the fluid
• Venturi effect has been demonstrated in cities where wind through the buildings has caused windows to get blown out! (higher pressure from the still air within the buildings pushes toward the moving wind in the street)

Friday, November 6, 2009

AGENDA:

• 8.4 Study Guide
• ScienceSaurus Review
• Read 8.5

ASSIGNMENT:

• Have a restful and helpful weekend!
• Remeber to study (read notes) some time during the weekend.
• Extra Credit! Take the online quiz for Ch.8 (see "Great Sites!")