In a hydraulic lift system,what must be the surface area of the piston if the pressure of 300 Pa is used to give a
desired upward force of 6000N?
Answers
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School Physics notes: Pressure in liquids and hydraulic machines
pressure in liquid fluids pressure in liquid fluids
FORCES 6. Pressure created by standing solid objects, pressure in fluids and hydraulic systems and P = F/A calculations
Doc Brown's Physics Revision Notes
Suitable for GCSE/IGCSE Physics/Science courses or their equivalent
This page will answer help you answer questions like e.g. What is a fluid? What is the formula for pressure? What causes pressure in liquids? How do you calculate pressure in a liquid? How do hydraulic systems work? What do we use hydraulic systems for?
Sub-index for this page
(a) Particle theory - revision of states of matter and density
(b) Pressure created by standing objects and in fluids, calculations using P = F/A formula
(c) Pressure in a liquid - density, depth factors and calculations
See also 7. Pressure & upthrust in liquids, why objects float/sink?
(d) Hydraulic systems - mechanical devices, transmission of forces in liquids, calculations
(e) Some applications of hydraulic systems
(a) Particle theory - revision of states of matter and density
Gases and liquids are fluids because the particles are free to move around from place to place.
In solids, the particles can just vibrate from a fixed position and cannot move to another position in the lattice of atoms.
(c) doc b (c) doc b (c) doc b
very low density FLUID high density FLUID highest density, but NOT a FLUID
Solids have the highest density, the particles are the closest together.
In fluids the inter-particle attractive forces are sufficiently weak to prevent a solid forming, allowing free random movement of the molecules of a liquid or gas.
Because of the weaker inter-particle force, the particles of gas will spread out to fill any space available giving gases by far the lowest density of the three states of matter.
The particles in a liquid are held much closer together because of greater inter-particle forces giving liquids a much greater density than gases.
Apart from water, liquid densities of materials are usually a few % less than that of their solid form.
The density of liquids is so high, with so little space between the particles, they are almost impossible to compress to a smaller volume.
Gases have so much space between the particles that they are readily compressed to a smaller volume.
The closer together the particles are, the more compact the substance is, the greater density of it.
See also Particle theory models of gases, liquids and solids and the particle diagram above.
Liquids have a uniform density (same throughout its bulk) which only increases very slightly under extremely high pressures because there is so little free space to squeeze the molecules into.
However, there is considerable space between gaseous particles and its is relatively easy to compress th