1

19 Vibrations & Waves

• Homework:

• RQs: 2, 11, 12, 13, 16, 18. Problem 1.

2

Simple Pendulum• T = period

• f = frequency

• f = 1/T

• L = length

• M = mass

• L x 4 T x 2

• T mass independent

3

Waves

• moving vibrations• Speed = frequency x length• Speed same as frequency & length

change, e.g. sound

4

Types of Waves

• Transverse Longitudinal(elastic, light) (elastic, sound)

• Video on slinky

5

Bow & shock waves

• Speed (boat, plane) exceeds wave speed

• Angle change with speed

• Video of shock waves – wiki

• Video bullwhip

6

doppler effect

• Pitch change due to motion

• Increase on approach

• Decrease with separation