• What happens when you squeeze a tube of toothpaste from the bottom of the tube? Why do you think that is?

BELLRINGER

• If you said something like “What you do at one end affects the other.” Then you’re on the right track.

ANSWER

• French Scientist, Philosopher, Mathematician

• Among his important works is Pascal’s Principle– Pressure is transmitted

throughout all parts of a fluid.

• Mathematically this can be simply stated as P1=P2

• How else could we write this?

BLAISE PASCAL

• Since pressure consists of a ratio between force and area, transmitting pressure through a fluid can create different forces if applied through different areas.

WHY DO WE CARE?

• Hydraulics work by sending pressure through a fluid, using a small force over a small area to exert a large forge over a large area.

• http://webphysics.davidson.edu/physlet_resources/bu_semester1/c23_pressure_pascal.html

HYDRAULICS

• When the button of a trash compactor is pushed, a force of 350 N pushes down on a 1.3 cm2 input piston, creating a force of 22,076 N to crush the trash. What is the area of the piston that crushes the trash?

TRY A SAMPLE PROBLEM

• You work for a major toy company and your boss has just asked you to create a toy that will allow your average 5 year old child (20kg) to step on a pedal and exert enough force to lift a 50 kg Power-Wheels like car, as if working as a mechanic. The maximum pressure the toy can contain is 2200 Pa before it ruptures. Sketch a model of your system and give dimensions for the pedal and the base that lifts the toy car.

BE CREATIVE