18.1 The Origins of the Reformation

11-3/11-4: Pascals & Bernoullis Principles What is fluid pressure and how is it related to motion?

1Anticipatory SetWhat will happen if you squeeze one side of the bag of water?

California StandardsScience Standard 8.8.c: Students know the buoyant force on an object in a fluid is an upward force equal to the weight of the fluid the object has displaced.Science Standard 8.2.e: Students know that when the forces on an object are unbalanced, the object will change its velocity.

3InputPascals principle: pressure increases by the same amount throughout an enclosed or confined fluid.hydraulic system: uses liquids to transmit pressure and multiple force in a confined fluid.Bernoullis Principle: the faster a fluid moves, the less pressure the fluid exerts.lift: an upward force.

4Input & Modeling

Transmitting Pressure in a Fluid

When force is applied to a confined fluid, the change in pressure is transmitted equally to all parts of the fluid.

5Input & Modeling

Hydraulic Devices

In a hydraulic device, a force applied to one piston increases the fluid pressure equally throughout the fluid.

6Input & Modeling

Hydraulic Devices

By changing the size of the pistons, the force can be multiplied.

7Input & ModelingComparing Hydraulic Lifts

3,000 NReading Graphs:

For Lift A, how much force must be applied to lift a 12,000-N object?

8Input & ModelingComparing Hydraulic Lifts

Lift A: multiplied by 4Lift B: multiplied by 2Interpreting Data:

By how much is the applied force multiplied for Lift A? Lift B?

9Input and ModelingComparing Hydraulic Lifts

The slopes gives the ratio of the lifting force to the applied force. The greater the slope, the more the lift multiplies force.Interpreting Data:

What does the slope of each line represent?

10Input and ModelingComparing Hydraulic Lifts

Lift A, because it multiplies force more than lift B.Drawing Conclusions:

Which lift would you choose if you wanted to lift a weight of 4,000 N?

11Input & Modeling

Hydraulic Brakes

The hydraulic brake system of a car multiplies the force exerted on the brake pedal.12Input & Modeling

Bernoullis Principle

Bernoullis principle states that as the speed of a moving fluid increases, the pressure exerted by the fluid decreases.

13Input & Modeling

Applying Bernoullis Principle

Bernoullis principle helps explain how planes fly.

14Input & Modeling

Applying Bernoullis Principle

An atomizer is an application of Bernoullis principle.

15Input & Modeling

Applying Bernoullis Principle

Thanks in part to Bernoulli's principle, you can enjoy an evening by a warm fireplace without the room filling up with smoke.

16Input & Modeling

Applying Bernoullis PrincipleLike an airplane wing, a flying disk uses a curved upper surface to create lift.

17C4U

Quick Quiz PPTGet out your whiteboard and marker!

18 HOMEWORK CONNECTION

Read pages 432-441 in your Science textbook.

Complete the Section 11-3/11-4 Review & Reinforce

Write a detailed SUMMARY of the section and complete the UNANSWERED QUESTIONS section of your notes.

Choose two of the remaining Depth & Complexity ICONS in your notes and explain how they relate to this section.

Here Comes ScienceThey Might Be GiantsJohn Linnell/John FlansburghHere Comes Science2009iTunes 10.0.1, QuickTime 7.6.6