Year 10 Physics

(ask questions on each state)

What are the properties of a solid?

• They have a fixed shape and cannot flow
• They cannot be compressed or squashed

Why are they like this?

• The particles cannot move from place to place
• The particles are close together and have no space to move into

What are the properties of a liquid?

• They flow and take the shape of their container
• They cannot be compressed or squashed

Why are they like this?

• The particles are free to move around each other
• The particles are close together and have no space to move into

What are the properties of gases?

• They flow and completely fill their container
• They can be compressed or squashed

Why are they like this?

• The particles can move quickly in all directions
• The particles are far apart and have space to move into

What are changes of state?

Changes of state are:

• solids melting into liquids
• liquids boiling into gases
• gases condensing into liquids
• liquids freezing or solidifying into solids

Evaporation is sometimes confused with boiling. They both involve liquids turning to gases, but evaporation is different. How?

• it occurs at any temperature - not just the boiling point
• it only happens at the surface of the liquid - not throughout like boiling
• boiling requires an energy input - whereas evaporation is the release of the molecules with the highest energy

What is the equation to workout the efficency of an electrical item?

efficiency = (useful power out ÷ total power in) × 100

Force = mass x acceleration

Work done = force x distance