Stretching and compressing

• How many forces are required to compress, bend, or stretch an object?

  More than one
• Why does it take multiple forces to deform an object?

  Because they must act in different directions
• What is the relationship between the force applied and the extension of an elastic object?

  The extension is directly proportional to the force applied
• What condition must be met for the relationship between force and extension to hold true?

  The limit of proportionality must not be exceeded
• What is meant by inelastic (plastic) deformation?


  A deformation that results in the object being permanently changed
• What happens to an object after inelastic deformation when the force is removed?


  The object does not return to its original shape
• What is the equation relating force, spring constant, and extension?

  Force = Spring Constant x Extension
• What are the appropriate units for force, spring constant, and extension in the equation?

  Force (N), Spring Constant (N/m), Extension (m)
• What type of energy is stored in a spring when it is stretched?

  Elastic potential energy
• What can extension be replaced with in the equation for spring force?

  Compression
• How do elastic and inelastic distortions differ?

  Elastic distortion is temporary, while inelastic distortion is permanent
• What happens to an object after elastic distortion when the forces are removed?

  The object reverts to its original shape
• How can you calculate the work done/stored in stretching a spring?

  Energy (J) = ½ x Spring constant (N/m) x Extension² (m²)
• What is the formula for calculating energy stored in a spring?

  E = ½ k x²
• When is there a linear relationship between force and extension?

  When an object is deforming elastically and has not reached the limit of proportionality
• When does a nonlinear relationship between force and extension occur?

  When the limit of proportionality has been exceeded and the object is undergoing plastic deformation
• What are the key differences between elastic and inelastic deformation?

  • Elastic deformation:
  • Temporary change
  • Returns to original shape
  • Inelastic deformation:
  • Permanent change
  • Does not return to original shape
• What is the process for calculating work done in stretching a spring?

  1. Use the formula: Energy (J) = ½ x Spring constant (N/m) x Extension² (m²)
  2. Substitute values for spring constant and extension
  3. Calculate the energy stored
• What are the conditions for linear and nonlinear relationships in force and extension?

  • Linear relationship:
  • Occurs when deforming elastically
  • Limit of proportionality not exceeded
  • Nonlinear relationship:
  • Occurs when limit of proportionality is exceeded
  • Object undergoing plastic deformation