GCSE Physics OCR B J259

P6.4: How does the particle model relate to pressure in fluids?

#P6.4.1

recall that the pressure in fluids causes a force normal to any surface

#P6.4.2

recall and apply the relationship between the force, the pressure, and the area in contact:

pressure (Pa) = force normal to a surface (N) ÷ area of that surface (m2)

#P6.4.3

recall that gases can be compressed or expanded by pressure changes and that the pressure produces a net force at right angles to any surface

#P6.4.4

use the particle model of matter to explain how increasing the volume in which a gas is contained, at constant temperature, can lead to a decrease in pressure

#P6.4.5

select and apply the equation:

pressure × volume = constant (for a given mass of gas at constant temperature)

#P6.4.6

describe a simple model of the Earth’s atmosphere and of atmospheric pressure, and explain why atmospheric pressure varies with height above the surface

#P6.4.7

**explain why pressure in a liquid varies with depth and density **

#P6.4.8

**select and apply the equation to calculate the differences in pressure at different depths in a liquid:

pressure = density × gravitational field strength × depth **

#P6.4.9

**explain how the increase in pressure with depth in a fluid leads to an upwards force on a partially submerged object **

#P6.4.10

**describe and explain the factors which influence whether a particular object will float or sink **

P6.3
How does the particle model relate to material under stress?
P6.5
How can scientific models help us understand the Big Bang?