1. Textbook: 13.1 Homework: pg 473 – 474: # 23 – 32
Vibrations and Waves
Textbook: 13.1
Homework: pg 473 – 474: # 23 – 32

2. Vibrations
A vibration is any kind of repeated motion which can be described by:
Amplitude:
Frequency:
Period:
All objects have frequencies they like to vibrate at called
Demo: Waves are created by vibrations.
Ex. Relationship between frequency and period

3. Vibrations
A vibration is any kind of repeated motion which can be described by:
Amplitude: A = Distance from equilibrium [m]
Frequency: f = # of cycles/second [Hz]
Period: T = seconds/cycle [s]
All objects have frequencies they like to vibrate at called natural frequencies
Demo: Waves are created by vibrations.
Ex. Relationship between frequency and period

4. Parts of a Wave

5. Parts of a Wave

6. Waves They are described by:
Ex. Draw examples transverse and longitudinal
Demo. Vibrations creating a wave (Vibrator and a string)
Demo. Slinky as a transverse and longitudinal wave

7. Waves
A wave is a disturbance that travels through a medium carrying energy. They are described by:
Amplitude (A)
frequency (f)
period (T)
wavelength () [distance of one cycle]
Ex. Draw examples transverse and longitudinal
Demo. Vibrations creating a wave (Vibrator and a string)
Demo. Slinky as a transverse and longitudinal wave

8. There are 2 kinds of waves:
Transverse:
Longitudinal:

9. There are 2 kinds of waves:
Transverse: Disturbance (vibration) perpendicular to motion of the wave
Longitudinal: Disturbance (vibration) parallel to the motion of the wave
Ex. Draw examples transverse and longitudinal
Demo. Vibrations creating a wave (Vibrator and a string)
Demo. Slinky as a transverse and longitudinal wave

10. Longitudinal wave:
the particles vibrate parallel to the direction of motion of the wave.
Transverse wave: the particles in the medium vibrate at right angles to the direction in which the wave travels

11. T = period [s]
∆t = duration [s]
f = frequency [Hz]
N = number of vibrations

12. The Universal Wave Equation
All waves (longitudinal and transverse) obey the same equation that relates the wavelength ( in m) frequency (f in Hz) and speed (v in m/s)

13. Pg Dolphins have a large repertoire of sounds that can be classified under two general types: those sounds used to locate objects, termed echolocation (sonar), and those emitted to express emotional states. Dolphins emit pulses and clicks in groupings at a rate of over 690 clicks per 2.3 s. The sounds have a frequency of typically 130 kHz
a) Find the period and frequency of emission of pulses.
b) Given that the speed of sound is 344 m/s, find the wavelength of the emitted pulse.

14. An FM station, BOOM, broadcasts radio signals with a frequency of 97
An FM station, BOOM, broadcasts radio signals with a frequency of 97.3 MHz. These radio waves travel at a speed of 3.00 × 108 m/s. What is their wavelength?