Forces and elasticity

• What can forces do to objects besides making them move?

  They can change their shape
• What determines if a shape change is temporary or permanent?

  The object and the forces applied
• What happens when you apply a force to an object?

  It may stretch, compress, or bend
• Why is more than one force needed to change an object's shape?

  To prevent the object from just moving
• What is done when a force stretches or compresses an object?

  Work is done and energy is transferred
• What type of energy is stored when an object is deformed?

  Elastic potential energy
• What does it mean for an object to be elastically deformed?

  It returns to its original shape after force removal
• What are objects that can be elastically deformed called?

  Elastic objects
• What happens to an object that has been inelastically deformed?

  It does not return to its original shape
• What is the difference between elastic and inelastic deformation?

  Elastic returns to shape; inelastic does not
• What equation relates the force on a spring to its extension?

  F = ke
• What does the spring constant, k, depend on?

  The material of the spring
• What happens to the extension of a spring when the force applied increases?

  It is directly proportional to the load
• What is the limit of proportionality in relation to springs?

  Maximum force before extension stops being proportional
• How is the spring constant measured?

  In N/m
• What should you be careful about when calculating with springs?

  Units for extension measurements
• How does the graph of force against extension behave after the limit of proportionality?

  The graph curves, showing non-proportionality
• What happens to the graph if the axes are reversed in extension force graphs?

  It still starts straight but curves upwards