Springs and Hooke’a Law

• Force equation


  spring constant x extension
• Force unit


  N
• spring constant unit

  N/m
• extension unit


  metres
• elastic deformation


  when an object will return to its original dimensions when the applied force is removed
• plastic deformation 


  when an object will not return to its original dimensions when the applied force is removed
• Hooke’s Law

  for a spring force and extension are directly proportional
• spring constant

  how stiff a spring is ,stiffer the spring the more force that is needed to causes a given extension
• extension


  Final length - original length
• Elastic potential energy


  energy stored in an object that is stretched
• elastic potential energy unit 


  Joules (J)
• Elastic potential energy equation

  1/2 x spring constant x extension^2
• Elastic limit


  point beyond which deformation is plastic and permanent
• limit of proportionality 


  when the spring stops obeying Hooke’s Law