1. Natural Length Extension Stretched Length No relationship between Force and stretched length Force is proportional to extension

2. Hooke’s Law (Simple Version) Hooke’s law says the EXTENSION is proportional to FORCE Extension (m) Force (N) Spring constant (N/m) “Stiffness”

3. Hooke’s Law (The one you need) Hooke’s law says the EXTENSION is proportional to FORCE Extension (m) Tension (N) Natural Length (m) Young’s Modulus (N) “Modulus of elasticity”

4. S p rings vs S t rings Vs SpringsStrings Can it be stretched? YES Can it be compressed? YESNO Uses Clocks, Pens, Mattress, Car Suspension, Slinky, Pogo Stick,... Shoe laces, cat toy, tying parcels, fishing, kites, musical instruments,.....

5. Puzzle Time!

6. Work Done Shows area under line/curve Force Displacement

7. Force Displacement Extension

8. ELASTIC POTENTIAL ENERGY!!!

9. 1) 2)

10. 3)

11. 4)i)

12. 4)

13. 5)

14. Independent Study Exercise A page 116