science A3 Flashcards
what is viscosity
How quickly a fluid can flow. So for example, ketchup has a high viscosity (thick) and orange juice has a low viscosity (thinner). ketchup is more viscus
How is friction in effect with viscosityz
The internal resistance or friction between the particles of the substance determines the AA eeeof that substance. The more friction - the more viscous (thicker) a substance is. The higher the viscosity of a substance, the slower it flows.
how does temperature affect viscosity
Increasing temperature lowers viscosity (makes it thinner)
Decreasing temperature increases viscosity (making it thicker)
whats a fluid
Any matter that has volume, no shape, and takes shape of container
what is density
the amount of stuff occupying a certain amount of space
formula for density and what units are used in its calculations
mass divided by volume
g/mL, g/cm3, g/cc, kg/m3
what is buoyancy? what is a buoyant force
buoyancy- tendency of an object to float when placed in a fluid
buoyant force- upward force, downward force and neutral
Plimsoll line
Ships are designed to float in all types of water, regardless of the density of the water. Plimsoll Line- shows how heavily a ship can be loaded in different water conditions.
how do hot air balloons work
As the air inside the balloon is heated, it becomes less dense than the surrounding air. The buoyant force of the air will push the hot air balloon upwards, until the buoyant force equals the force of gravity
Compressibility
extent to which a substance (solid , liquid or gas) can be squeezed by pressure.
Objects under compression tend to deform in shape
particle model of matter in Compressibility between a liquid and gas
when a force is applied to the particles, much more compression takes place in gas than in liquid. gas particles have more space to move. very little compression occurs in liquids. Materials in a liquid state are said to be incompressible; that is, they cannot be compressed easily. (There is much more space between particles in a gas than there is between particles in a liquid.)
what is pressure and 3 main points
Pressure measures the amount of force applied to a certain area.
Pressure is exerted in all directions
The larger the force, the greater the pressure.
The smaller the area, the greater the pressure.
how is pressure calculated
force (f) divided by area (a)
Force is measured in newtons (N)
Area is often measured in square metres (m2)
Pressure is newtons per metre square (N/ m2)
also called a pascal (Pa), after Blaise Pascal
what is Pascal’s Law
Pascal’s Law states that if you apply pressure to fluids that are confined (or can’t flow to anywhere), the fluids will then transmit (or send out) that same pressure in all directions at the same rate.
what is a hydraulic system
one that uses the pressure of a liquid to preform mechanical work
