Physics - EDEXCEL IGCSE - Solids Liquids and Gases

Section 5 - Solids, Liquids, and Gases:

This is one of the simplest sections. As such there is only a small amount of information that you need to know.

p = m / v

density = mass / volume

p  = F / A

pressure = force / area

The pressure at a point in gas or liquid at rest acts equally in all directions.

p = h * p * g

pressure difference = height * density * gravitational field strength

Particles within a liquid have random motion within a closely packed irregular structure.

Particles within a solid vibrate about a fixed position within a closely packed regular structure.

Brownian Motion - this is the principle that particles move randomly about a space and that when particles collide they exert a pressure on a surface.

Kelvin:

We are all familiar with the celsius and Fahrenheit scales which are used to measure temperature. In science, another scale called the kelvin scale is also used. The scale starts at the lowest temperature possible in the universe.

There is an absolute lowest temperature of -273ºC

This is where particles have no energy at all and, therefore, are not moving at all.

0 kelvin = -273ºC

higher temperatures means higher pressure.

pressure₁ / kelvin₁ = pressure₂ / kelvin₂

pressure₁  * volume₁ = pressure₂ * volume₂