120 likes | 597 Vues
Hydraulics. and the use of liquid pressure. The important features of pressure in liquids. Liquids will transmit pressure throughout the liquid, regardless of the shape of the container A force therefore can be applied wherever you want it
E N D
Hydraulics and the use of liquid pressure
The important features of pressure in liquids • Liquids will transmit pressure throughout the liquid, regardless of the shape of the container • A force therefore can be applied wherever you want it • The force can be multiplied according the the area of the pistons used to push down on the water
Examples of the use of hydraulics • Car brakes • Car jacks • Fork lift trucks • Lifts • bulldozers • Television cameras
How car brakes use hydraulics • A small force on the brake pedal will act on a piston with a small area • The small piston pushes against the brake fluid • The pressure exerted is transmitted to all parts of the liquid • The pressure acts against four bigger pistons with larger areas • The large pistons will multiple the force and cause the brake pads to push against the wheels • As pressure is transmitted equally throughout the liquid, each brake works evenly too
Hydraulic brake • The diagram shows a simple brake where a pedal will push down on the smaller master piston • The force pushing down will put the liquid under pressure • The pressure is transmitted through the liquid and against the slave piston • The pressure causes the slave piston to exert a force where it is needed
Using the formula P=F/A • What is the pressure exerted on the liquid by the slave piston? Answer: Pressure = 10N / 5cm2 = 2 N/cm2 • Calculate the area of the slave piston that will lift a 100N load Answer: Area = force / pressure = 100N / 2 N/cm2 10N Slave piston Master Piston Is 5 cm2
More questions on hydraulics • What will the force (F1) need to be to exert a pressure of 20 N/cm2 ? • Calculate the weight (F2) that can be lifted by the slave piston. Answers:1. Force = 20 N/cm2 x 10cm2 = 200N 2. Force = 20 N/cm2 x 100cm3 = 2000N Master piston = 10cm2 Slave piston = 100cm2
Summary of the principles of hydraulics • Pressure is transmitted throughout a liquid • A force may be applied anywhere to the liquid • All hydraulic systems use a small master piston and a large slave piston • A small force is used to create a very big force • The small master piston is used to apply a force • The slave piston is always bigger than the master piston • The larger slave piston will multiply the original force put on the master piston
This powerpoint was kindly donated to www.worldofteaching.com http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.