1. Warmup includes Tacoma Narrows Bridge Video

2. Warmup Turn in your homework: page 513 (1-9) Prepare for an extreme video on waves. Questions for warmup will follow.

3. Warmup 1) What features could be built into a bridge to prevent this? 2) Discuss the importance of this bridge disaster in the history of bridge building.

4. What is a Wave? Mechanical Wave – a disturbance in matter that carries energy from one place to another. Mechanical waves require a medium (matter through which they travel). Most waves are caused by vibrating objects.

5. What is a Wave? Three types of mechanical waves (see your foldable): Transverse Longitudinal Surface

6. Properties of Waves Most common properties used to describe waves: Amplitude Wavelength Period Frequency Wave Speed

7. Amplitude Amplitude is the maximum distance the medium move away from its rest position. The amplitude of a transverse wave is the maximum distance from the rest position to a crest or trough.

8. Amplitude Amplitude is the maximum distance the medium move away from its rest position. The amplitude of a longitudinal wave is a measure of how compressed or rarefied the medium becomes.

9. Wavelength The distance between one point on one wave and the same point on the next cycle is its wavelength. Represented with a λ (lambda) in equations.

10. Wavelength Both amplitude and wavelength are measurements of distance. Transverse measure from crest to crest or trough to trough. Longitudinal measure from one compression to the next.

11. Period The time it takes a complete wave cycle to occur. AKA the time needed for one full wavelength of a wave to pass a certain point. Expressed in seconds (time measurement).

12. Frequency Frequency –The number of complete waves that pass a given point in a given time. AKA number of vibrations/cycles per second. Frequency is measured in hertz (Hz), = 1 cycle per second.

13. Wave Speed You can calculate the speed (v) of a wave by multiplying the wavelength ( λ ) and the frequency (f): v = f x λ The units for wave speed are m/s.