1. Hooke ’ s Law

2. Elasticity: The ability of an object to return to its original shape after the deforming force is removed.

3. Types of Elasticity: Extension – Stretch Compression – Squeeze Torsion – Twist Flexion - Bend

4. Extension Trampoline springs

6. Compression Shock absorber

8. Torsion Rat Trap

10. Flexion Diving board

12. Robert Hooke: In 1678 Robert Hooke studied elasticity and found that within the limits of perfect ELASTICITY Strain is directly proportional to Stress. This is known as Hooke ’ s Law

14. Stress: The applied force or the weight of the object that causes a spring to stretch. Stress is a measurement of Force and is always measured in Newtons (N) F = ma

15. Strain: The change in shape The amount of stretch in a spring. Strain is a measurement of Distance and is always measured in Meters.

16. Hookes experimental set up

17. Our experimental set up

18. Formulas: F Change in Force Measured in (N) Elastic Constant Labeled as Newton/meters (N/m) K =F / L F = L x K L = F/K K L Change in length Measured in (m)

19. Elastic Limit: The point at which too much stress is applied and the spring will not return to its original shape.

21. DON ’ T DO THAT !!