Elasticity and Spring Extension

• Explain, using examples, that stretching, bending, or compressing an object requires the application of more than one force.
• Describe the particle model and use it to explain how elastic and plastic deformation differ when an object is deformed by stretching forces.
• Describe how force and extension are related for springs and other simple systems.
• Describe how to observe and measure the way forces affect a spring's extension.
• Describe the difference between force-extension relationships for linear and non-linear systems.
• Recall and apply the relationship linking spring constant, extension and force for systems that behave linearly:

$F = k \times x$