Materials under stress

• Explain the need for multiple forces to stretch/bend/compress objects. • Use the particle model to explain elastic vs plastic deformation. • Describe the force-extension relationship and experimental measurement. • Distinguish between linear and non-linear force-extension systems. • Apply the spring constant equation for linear systems: $force\ (N) = spring\ constant\ (N/m) \times extension\ (m)$ • Calculate work done in stretching by area under force-extension graph. • Apply the stored energy equation: