Wide gap = small diffraction effect

1. As we go through these slides, you will make a study dictionary of some of your vocabulary words. • For each word you will draw a picture to help you visualize what it means. • Vocabulary words: reflection, angle of incidence, angle of reflection, refraction, diffraction, interference, constructive interference, destructive interference, standing wave, nodes, antinodes, resonance, seismic waves, primary waves, secondary waves, surface waves, and seismographs

4. DIFFRACTION Narrow gap = large diffraction effect Wide gap = small diffraction effect Large wavelength = large diffraction effect

5. INTERFERANCE • DESTRUCTIVE • INTERFERANCE • Destruct = destroy • 2 waves combine to make a SMALLER amplitude CONSTRUCTIVE INTERFERANCE • Helping each other • 2 waves combine to make a LARGER amplitude

6. STANDING WAVES • When an incoming wave and reflected wave combine at a specific place, the wave APPEARS to be standing still. • In reality, the waves are just passing through each other.

8. Water in Bucket • Yesterday we watched water in the bucket continue to vibrate long after the disturbance was over. This is an example of resonance. • Examples: Pushing someone in a swing, jumping rope, rolling a bowling ball back and forth with someone

9. Seismic Waves

10. Surface waves