1. P H Y S I C S Chapter 7: Waves and Vibrations Section 7A: Hooke's Law and SHM of a Mass-Spring System

2. Discovered the cell Hooke’s Law (1635-1703) Hooke’s Law Demo Robert Hooke

3. Hooke’s Law Spring force is directly proportional to displacement of spring spring constant slope = k

4. Hooke’s Law Equation

5. Simple Harmonic Motion (SHM) SHM = periodic vibration about an equilibrium point Amplitude = max displacement x o = 0 equilibrium amplitude +x amplitude -x

6. Max force occurs at amplitude Zero force occurs at equilibrium Force max force xoxo -x+x max force zero force

7. Max velocity occurs at equilibrium Zero velocity at amplitude Velocity xoxo -x+x max velocity zero velocity zero velocity

8. Period of a Mass-Spring System

9. Period is independent of amplitude

10. In-Class Problem #1 Determine the mass suspended at rest from the spring. m = 30.6 kg x = -1.2 m k = 250 N/m 

11. In-Class Problem #2 A 2 kg mass is pulled back 0.5 m from equilibrium with a force of 60 N. Determine the period of oscillation. k = 120 N/m T = 0.81 s

12. Assignment Problem Set 7A 7A-7B Quiz (Simple Harmonic Motion)