Science at key stage 3    (Year 9)

• explain the relationship between force and area, eg in terms of lying on a bed of nails
• apply the quantitative relation between pressure, force and area to a number of situations, eg skis, sharp blades

• show, by the ability to apply 'reverse logic', that they have grasped the key ideas of pressure

• describe some effects and uses of gases under pressure, eg car tyres, aerosols, pneumatic systems
• apply the model of the particle theory of matter to explain the behaviour of gases under pressure

• apply the particle model of matter to explain why liquids are incompressible and gases are compressible
• apply the concept of transmission of pressure to predict the resulting force
• describe some effects and uses of liquids under pressure, eg fire hoses, hydraulic systems

• describe an effect of atmospheric pressure or underwater pressure

• show by the links they make that they have grasped the key ideas

• describe how to make a task easier by increasing the distance between the effort and the pivot
• identify levers in a number of household devices

• describe the arrangement of muscles on the arm and associate them with the parts of a lever
• explain how an antagonistic muscle pair works

• describe how an object can be kept in balance, eg human body, crane
• apply the idea of the turning effect of a force to everyday situations, eg lifting heavy objects

• plan to take appropriate measurements
• present results in a way which helps them identify patterns
• explain, in terms of experimental technique, how anomalous results might have occurred
• recall the principle of moments and apply it to a range of situations

• show, by their answers, that they have grasped the key ideas