Hooke's Law (Cambridge (CIE) O Level Physics) : Revision Note

Hooke's Law

• Hooke’s law states that:

  The extension of a spring is proportional to the applied force

• Where:

  • F is the force applied

  • k is the spring constant

  • x is the extension of the spring

• The spring constant is the force per unit extension

  • The units are N/m

  • The spring constant is a measure of how stiff the spring is

• Directly proportional means that as the force is increased, the extension increases 

  • If the force is doubled, then the extension will double

  • If the force is halved, then the extension will also halve

• The limit of proportionality is the point beyond which the relationship between force and extension is no longer directly proportional 

  • This limit varies according to the material

Hooke's Law states that a force applied to a spring will cause it to extend by an amount proportional to the force