1. Simple Harmonic Motion
Simple Harmonic Motion – Vibration about an equilibrium position in which the restoring force is proportional to the displacement from equilibrium.
At the equilibrium position, velocity reaches a maximum.
At maximum displacement, spring force and acceleration reach a maximum.
The direction of the force acting on the mass (Felastic) is always opposite the direction of the mass’s displacement from equilibrium.

2. Hooke’s Law
Restoring Force – The spring force always pushes or pulls the mass back toward its original equilibrium position.
The restoring force is directly proportional to the displacement of the mass.
Hooke’s Law Equation:
Felastic = -kx
Spring force = -(spring constant x displacement)
The negative sign in the equation signifies that the direction of the spring force is always opposite the mass’s displacement.

3. The Simple Pendulum
A simple pendulum consists of a mass called a bob, which is attached to a fixed string.
The restoring force for a pendulum is a component of the bob’s weight.
For small angles (< 15-20°), the pendulum’s motion is simple harmonic.
In the case of a pendulum, gravitational potential energy, rather than elastic potential energy, increases as a pendulum’s displacement increases.

4. Types of Waves Wave – A vibration in time and space.
Mechanical Wave – A wave that propagates through a deformable, elastic medium.
Medium – The material through which a disturbance travels.
Pulse Wave – A single, non-periodic disturbance.
Periodic Wave – A wave whose source is some form of periodic motion.

5. Types of Waves (cont.)
Transverse Wave – A wave whose particles vibrate perpendicularly to the direction of wave motion.

6. Types of Waves (cont.)
Longitudinal Wave – A wave whose particles vibrate parallel to the direction of wave motion.

7. Characteristics of Waves
Wave Properties:
Transverse waves - Sine wave

8. Characteristics (cont)
Crest – The highest point of a wave.
Trough – The lowest point of a transverse wave.
Amplitude – The greatest distance that particles in a medium move from their normal position (rest position) when a wave passes.
Wavelength – The distance between any two successive identical parts of a wave.
Rest Position – The position of the medium without any disturbance.

9. Parts of a wave
Crest
Wavelength
Amplitude
Trough
Rest Position

10. Waves (cont)
Wave Speed – The speed at which a wave passes through a medium.
The units for wave speed are m/s.

11. Waves (cont) Period – The time required for one full wavelength
Frequency – The number of vibrations that occur in a 1s time interval.
The unit for frequency is Hertz (Hz). This means per second.

12. Wave Interactions
Interference - The net effect of the combination of two or more waves.
Constructive Interference – Interference between two or more waves in which amplitudes are additive and the resultant wave is larger than any of the original waves.

13. Wave Interactions (cont.)
Destructive Interference - Interference between two or more waves in which amplitudes are subtractive and the resultant wave is smaller than any of the original waves.

14. Waves Interactions (cont)
Doppler Effect – An observed change in the frequency of a wave when the source or observer is moving.

15. Wave Interactions (cont)
Standing Wave – A wave pattern that results when two waves of the same frequency, wavelength, and amplitude travel in opposite directions and interfere.
Node – A point in a standing wave where minimum vibration occurs due to destructive interference.
Antinode – A point in a standing wave where maximum vibration occurs due to constructive interference.

16. Wave Interactions (cont)

17. Wave Interactions (cont.)