11 Rotation

14 A sand scorpion

How does a horseshoe bat detect a moth in total darkness?4.1 governed by Newtons laws, exist only within a material medium ()governed by Maxwells laws, require no material medium to existall travel at c = 299,792,458m/s4.2 transverse displacement wave ()longitudinal displacement wave ()

Wave trainpulse

6An earthquake. radiates energy in the form of. P-waves, which are longitudinal vibrations like sound, S-waves, which are transverse vibrations P (primary) waves, which are similar to sound waves, and S (secondary) waves, which are a kind of shear wave. P waves travel between 6 and 13 km/sec. S waves are slower and travel between 3.5 and 7.5 km/sec. :

4.3

2D3D

Snapshot at t = 0 (or any other instant)y = y(t) at a fixed position

Why picking the sine waveNeed a videotape to show it in real time.Wavelength and angular wave number wavelength ():

Angular wave number(k):

k Period, angular frequency, and frequency f

T 4.4 The wave speed

Traveling WaveA left-going wave

A sinusoidal wave

4.5

II

II

Fourier Analysis

The Principle of Superposition for Waves4.6

II

4.7

Fully constructive and fully destructive interference

(exactly in phase/out of phase) / node/antinode

4.8

II

4.9 A string of length Ln: harmonic number

2D3D

4.10

Sonar, Seismic Waves and Ultrasound

4.11

Bulk ModulusB

apparent angle Displacement amplitude of an air element

4.12

4.13 Fully constructivedestructive interference(a)P1= 0, P2= D =1.5

P1 = 0, P2= (1.5/)2= 3(b) N = 6 around the circle

4.14 IntensityThe Sound Level

The Decibel Scale

The WHO the loudest concert

The Who: 120 dB : 92 dB

I1: I2 = 630!4.15

pipe

(a)

(b)

4.16 Beats

52For the difference frequency you can just say that you get a minimum when the modulating term reaches zero, which it does twice per cycle.

6.17 Beats - II4.18 The Dopper Effect(a) Detector moving; source stationary

(a)

Source moving; detector stationary

(general) (low speed) (b)

Mach Cone/Shock Wave Mach Number4.19 f = 1250Hz v = 242m/s (a)f

(b)f (a)fm when fbd = 83kHz(b)fbe when fbd = 83kHz

Vb = 9 m/s vm= 8 m/s 604.20

magnitude The M87 galaxy

200 ly

VPath difference vs. phase difference

The earths bow shock