Mr. Bouyer

Day 1 | Day 2 | Day 3 | Lab | Vocabulary Test | Motion WebQuiz

Pressure Fluid Barometer	Suction Buoyancy	Archimedes' Principle Hydraulics Bernoulli's Principle

Pressure: a force that acts over a certain area.

Pressure = Force / Area

What phases of matter are fluids?

Fluid - matter that is able to flow.

Fluids exert pressure because of the motion of their particles.

Example: Air molecules colliding with the inside of a basketball press against the material. The bounce of the ball can be adjusted by adding or removing air molecules. With more air in the ball, it does not compress as much when dribbled and will bounce higher. With less air, there is less pressure against the inside of the ball and it will bounce less. What happens if a basketball with no air in it is dribbled?

The pressure exerted by air at sea level is 10.13 N/cm².



• 1 Newton is the force needed to accelerate one kilogram of mass at one meter/second/second.
• In other words, 1 N = 1 kg X 1 m / s²
• Atmospheric pressure is commonly reported by the weatherman as "barometric pressure". The units reported are inches of mercury, obtained with a barometer. See a basic barometer diagram.

Practice problem: At sea level, what force is acting on a surface of 900 square centimeters?

Suction is a result of unequal pressure. While suction appears to "pull" objects, air pressure can only push. A fluid will move from an area of high pressure toward an area of low pressure.

In-class Assignment 241:
This assignment must be turned in by the end of class today to receive credit.
Scoring criteria

1. How many tons of air pressure are acting on your body at sea level?

   Air pressure is acting on about 1100 cm2 of your body. Pounds = Newtons / 4.45 1 ton = 2000 pounds.

2. Given two containers of water, write a complete set of directions explaining how to siphon the water from one container to the other.
3. You are drinking a soda through a straw. Explain what you do that causes the soda to move up the straw.
   (You cannot use any form of the word "suction" in your answer.)

Day 2

Archimedes' Principle:

The buoyant force is equal to the weight of the fluid displaced by an object.

• An object submerged in a fluid will displace a volume of fluid equal to the volume of the object.
• An object will rise in a fluid if its density is less than that of the fluid.
• An object will sink in a fluid if its density is greater than that of the fluid

Experiment withbuoyant force.

Hydraulics: the study of the pressure exerted by fluids.

Pressure is transmitted equally in all directions in a fluid.
Hydraulic devices take advantage of this property.

Flight Engineer

Bernoulli's Principle - The pressure in a moving stream of fluid is less than the pressure in the surrounding fluid. In other words, the faster a fluid moves, the less pressure it exerts. Jumbo jetsand kitesstay in the air because of Bernoulii's Principle.

What does airhave to do with flight?

Experiment with the control surfaceson an airplane.

Touran air-traffic control tower.

What makes flight possible?
(This is a very detailed website. Browse the introduction for topics of interest.)

Homework Computer Assignment 242:
This assignment must be completed by the beginning of class tomorrow to receive credit.
Scoring criteria

1. Make a PowerPoint file with the following slides:
   1. Make a PowerPoint slide showing a block of wood with a density of 1 g/cm³ being held below the surface of water by a hand.
   2. Duplicate the first slide.
      • Remove the hand.
      • Tell what happens to the block when it is released.
   3. Paste the picture of the helium-filled balloons on this webpage onto a new slide.
      • Place a red arrow under the balloons showing the direction they would move if released.
   4. Duplicate the second slide.
      • Place a blue arrow on the second slide representing a wind blowing from the left side of the slide.
   5. Duplicate the third slide.
      • Place a green arrow on the third slide representing the direction the balloons would move.
   6. Put an introduction slide at the beginning showing your name and the assignment number.

• Save this PowerPoint file on your computer.
• Show the PowerPoint presentation to your science facilitator.

When everyone at your table has completed the assignment, ask your facilitator for two apples and some string. Tie a 2-foot string to each apple stem. Hang the apples so they are about one inch apart. Blow directly between the apples. Write a paragraph explaining your observations.

Day 3

Who made the first non-stop flight across the Atlantic Ocean?

Test Your Concept Understanding: Use ancient flyers to answer the question: What do the words "Pterosaur" and "Pterodactyl" mean? Go to a wind tunnel to answer this question: What shape of wing provides the best "lift"? Read about the Wright Brothers. Exactly when did the Wright Brothers make the first airplane flight? Who was flying the plane? How long was the plane in the air? Use Principles of Aeronautics to find answers to the following. On what month, day, and year did the first artificial satellite orbit the earth? What was the satellite called? Who is credited with making the first diagram of a parachute? Who rode the winged horse, Pegasus? How did the Frisbie get its name?

• Understanding Air Pressure - USA Today Weather
• Aerodynamics - NASA Glenn Research Center
• Science Fun With Airplanes - Ohio State University 4-H Extension
• Airplanes and More - The Boeing Company
• Flapping-wing flying machines - Ornithopter HomePage
• Air Traffic Control System Command Center - FAA
• The Best Paper Airplane In The World - By: Michael O'Reilly