Elementary 8 SCPY159y

Physics 8 SCPY1598.1 8 2 8.2 8.3 8.4

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Elementary 8 SCPY159y

Physics 8 SCPY1598.1 8 2 8.2 8.3 8.4

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8.1

( f di t b ) (source of disturbance) (medium)

8.1

8.1

8.1

8.1

Elementary 8 SCPY159y

Physics 8 SCPY1598.1 8 2 8.2 8.3 8.4

. .

8.2

8.2

(transverse wave)

(longitudinal wave)

()

()

wave

(A ld (Auld

Lang Syne )

8.2

Elementary 8 SCPY159y

Physics 8 SCPY1598.1 8 2 8.2 8.3 8.4

. .

8.3

8.3 :

(oscillation)

() (cycle) (cycle)

8.3 : (frequency, f) (Hz)1 Hz = 1 /

8.3 :

(frequency, f) 1 (frequency, f) = 1f

T (period, T) T

(Hz) () () ( )

()

()T = 60 s f = 1/60 = 0.0167 Hz() T = 1 hr = 3600 s

f = 1/3600 = 2.78 x 10-4 Hz f 1/3600 2.78 x 10 Hz () T = 12 hr = 4.32 x 104 s ( )

f = 2.31 x 10-5 Hz

8.3 :

(wavelength, )

8.3 :

(wave velocity)

8.3 :

T T

v

s vT=vT = vT =v f

T = =T

8.3 :

=v f

f 2f 2f

() ()

() ()

8.3 : (amplitude, A)

: 1) :

2) :

8.3 :

2 2E A f2 2E A f

8.3 :

2 22 2E A fEPt

=t

2626 ... . 25472547 2626 ... . 25472547

( 200,000 ) () ()

TsunamiTsunami

TsunamiTsunami

(

))

30 30

TsunamiTsunami

8.3 :

2 2E A fEP =Pt

P Q

8.3 : /

( ) (intensity, I)

E PtIIA A

= =

P Q P Q

8.3 : PI

24

PIr=

224P

I r r 21 1 22 12

4I r rPI r

= = 2 1224 r

Ear trumpet

ear trumpet

Elementary 8 SCPY159y

Physics 8 SCPY1598.1 8 2 8.2 8.3 8.4

. .

8.4 1. 2. 3. 4. 4.

8.4 (wavefront) (wavefront) (ray)

8.4 : (( )

8.4 (law of reflection)

1)

1 2 =1 2 2)

8.4 :

8.4 :

8.4 :

(Snell's law)

sinv 1 1 12 2 2

sinsin

vv

= =

8.4 :

8.4 :

(total internal reflection)()()

8.4 :

o 90o

8.4 :

8.4 : .

8.4 : (superposition)

" "

8.4 : (superposition) " "

8.4 :

8.4 :

! !

8.4 :