Forces and Elasticity

• What is it called when an object returns to its original shape after the forces acting on it were removed?

  elastically deformed
• What is it called when an object does not return to its original shape after the forces acting on it were removed?

  inelastically deformed
• What is the limit of proportionality?

  The maximum amount of force an object can stand without being deformed. You can tell when an object passes its limit on a graph when the line is no longer straight
• What is the equation that applies to the linear section of a force-extension graph?

  force = spring constant x extension
• What does the spring constant of spring show?

  How easy it is to stretch a spring - The higher the spring constant the stiffer the spring
• What is needed to change the shape of an object?

  More than one force must be applied to that object (e.g. a spring must be pulled from both ends to stretch it)
• What is an example of an inelastic material?

  Certain types of polymers
• The extension of an elastic object is directly proportional to what?

  The applied force - they have a linear relationship and produce a straight line on a graph
• The higher the spring constant the stiffer the spring
• What does a force that stretches or compresses a string do?

  It stores elastic potential energy in the spring
• The amount of work done and the energy stored in the object are equal , unless the object has gone past the limit of proportionality (Or been elastically deformed)