1. Resonance, Doppler effect

2. Electromagnetic (EM) Waves
Unit Overview
Does not require
a medium; can
travel in a vacuum
Waves
Requires
a medium
Mechanical Waves
Electromagnetic (EM) Waves
Moves
Perpendicular
Moves parallel =
Transverse
Longitudinal
Light wave
Ocean wave
Sound wave

3. Resonance Activity

4. Resonance All elastic objects have natural frequencies
of vibration that are determined by the
materials’ compositions and shapes.
When energy is transferred at the natural frequencies, there is a dramatic increase of amplitude called resonance.

5. When the frequency of an applied force, including the force of a sound wave, matches the natural frequency of an object, energy is transferred very efficiently. The condition is called resonance.

6. Breaking Glass
Watch video

7. Doppler Effect
A change in the observed frequency of a wave caused by the relative motion between the source and the observer
The frequency is higher as the object moves toward you
The frequency is lower as the object moves away.

9. Sound from:
A stationary object
A moving object

11. An ambulance moving towards you is sounding its siren, which has a frequency of 1500 Hz. The pitch that you perceive from the siren sounds is___________.
a. not enough information b. higher than 1500 Hz c. lower than 1500 Hz d. equal to 1500 Hz