1. Hydraulic and Pneumatic Systems

2.  They are fluids in a closed system.  The fluid can move around with in the system but can not enter or leave the system. The blood inside your body is a confined fluid Can you think of any other examples of confined fluids? Water in an open cup is not a confined fluid

3.  A small downward force on a piston in a closed container causes pressure to be exerted in all directions.  This pressure is the same in all directions so the force can build and be transmitted to every part of a fluid

4.  Pascal’s Principle- when a confined fluid is subjected to an externally applied pressure, the pressure at all points within the fluid increase by the applied amount Blaise Pascal: Invented the hydraulic press and the syringe

5. 1. Hydraulic system: is a confined pressurized system that uses moveable liquids 2. Pneumatic system: is a confined pressurized system that used moving air or other gasses such as carbon dioxide. Examples: read section 5.8 in textbook Hydraulic system: Pneumatic system:

6.  The force applied to a system can be multiplied to exert a much larger force to do work. To make a hydraulic system more effective you have to change the relative size of the cylinders. If the area of the large piston is nine times larger then the area of the smaller piston, the force on the larger cylinder is nine times larger then the force applied to the smaller piston.

7. Area of small piston: A=πr 2 A= (3.14)(5cm) 2 = 78.5 cm 2 Area of the large piston: A= (3.14)(15) 2 = 706.5 cm 2 706.5/78.5= 9 -this tells us that the area of the larger piston is 9 times larger than that of the smaller cylinder - 9 x 40N = 360N = the maximum weight that can be lifted by the large piston.

8. 1.What is the maximum weight that could be lifted on the large piston? 2.How far will the small piston have to be moved downward to lift the large piston 1 cm? Hint: The area of the piston is calculate using the formula A=πr 2 π=3.14 r= radius Small cylinder diameter= 10cm Large cylinder diameter= 30 cm

9.  By increasing the pressure on a gas the particles can be pushed close enough together that the gas will change to a liquid Example?  Propane  Oxygen for oxygen masks in an airplane

10. Small piston has a diameter of 50cm and the large piston has a diameter of 100cm To calculate the area of each piston we use the formula: A=πr 2 π=3.14 r= radius Small piston area= (3.14)(25cm) 2 = 1962.5cm 2 Large piston area=(3.14)(100cm) 2 = 31400 cm 2 31400/1962.5= 16 –the large piston is 16 times larger than the small piston If there was a force of 30 N pushing down on the small piston how much force would the large piston be pushing up? 30N x 16 = 480N