1. Pressure, Pascal’s Law, Hydraulic & Pneumatic Systems

2. Pressure force pushing on a surface the surface can be a solid, liquid or a gas if you keep the force constant and change the amount of area you exert the force the pressure changes

3. Problem: if you were drop a raw egg from the top of the building how would you prevent it from breaking?

4. Demo’s https://www.youtube.com/watch?v=jWtwdW _NSf0 https://www.youtube.com/watch?v=jWtwdW _NSf0 https://www.youtube.com/watch?v=wuSSe0A QO0khttps://www.youtube.com/watch?v=7dI ge3q https://www.youtube.com/watch?v=wuSSe0A QO0khttps://www.youtube.com/watch?v=7dI ge3q https://www.youtube.com/watch?v=7dIge3qC Udw https://www.youtube.com/watch?v=7dIge3qC Udw Crush the can

5. Pascal’s Law states that when force is applied to a fluid in a confined/contained area the pressure is transmitted equally throughout the fluid in all directions P = F ÷ A P = pressure (Pa) Pascals F = Force (N) A= Surface Area (m 2 )

6. Pascal’s Law con’t… because liquids don’t compress easily they are good transmitters of force for gases to transmit a force they must first be compressed

7. How much pressure do you exert? Convert your body weight to N Trace your shoe on a piece of paper Estimate the area by measuring the base and the height of the shoe Calculate the area Apply it to the formula & calculate p= F ÷ A

8. Hydraulic Systems uses liquid under pressure to move loads; Advantage: a small force over a large area can create a large force over a small area Closed system – self-contained collection of parts/ confined space https://www.youtube.com/watch?v=r-_- kbwxKtU https://www.youtube.com/watch?v=r-_- kbwxKtU

9. Hydraulic Systems con’t Fluids transmit a force through a pipe or hose to move to other subsystems (i.e. levers) Increases the force applied, thus increasing the mechanical advantage (MA) used to move heavy objects (vehicle on a service station lift) Uses liquids because this fluid can change shape and doesn’t compress easily

10. Mechanical Advantage of Hydraulic Systems determined by the relative sizes of the pistons the ratio of the output (load)/area of the input(effort) or area of output(load)