# WAVE AND SOUND SAMPLE TEST KEY x km

```WAVE AND SOUND SAMPLE TEST KEY
1
! !!!!!!!
4
3
!l = 66cm ... the next resonant would be at !
4
1.!!it is resonating at the fundamental !!l =
2. (A) !!n =
c
v
v=
c 3.00!x!10 8
=
n
1.44
m
s
= 2.08!x!10 8
m
s
!!!!!!(B)!v =
x
t
t=
x
6, 091km
=
= 0.0293s !!!
v 2.08!x!10 5 kms
# 1 &
(C)!!1.44 sin ! c = 1.00 sin 90.0 o !!!!! c = sin "1 %
= 44.0 o
\$ 1.44 ('
3. Look at your notes
4.!! f = fs
v ± vo
v + vo
!!!!! f = fs
!
v ± vs
v ! vs
f = 847Hz
343 + 27.0
= 992Hz
343 ! 27.0
v
343 ms
=
= 1.309m
f 262Hz
1
1
l = ! " 0.4d l = (1.309m) " (0.4 * 0.0220m) = 0.318m
4
4
5.!!v = f ! ! =
6.!l =
5
2
! !! ! = l
2
5
7.!!(A)! f = fs
!!v = f ! ! !!v =
v ± vo
v ! vo
!!!!! f = fs
!
v ± vs
v ! vs
322
= (298.33 m s ) = 340 m s ! vo
355
FT
v
!!!! f = =
m
!
L
322Hz = 355Hz
FT
m
l =
2
l
5
55.8N
0.00155kg
1.25m = 424Hz
2
(1.25m)
5
340 ! vo
!!!!!!!!!!!(B)!Doppler!effect
150, 000m %
"
340
!
\$#
'
3600s &
vo = 340 m s ! 270.6 m s = 69.40
m 3600s 1!km
x
x
= 250 km
h
s
h
1, 000m
8. (A) in your notes (B)look at your notes.... how does a standing wave form? (C) in your notes
9.!!v =
x
tup
!!!x = vtup !!!!y = vot +
340(3.76 ! t) =
t=
1 2
1
at !!!!!vtup = gt 2 !!!!!!tup = 3.76s ! t
2
2
1
9.80t 2 !!!!!4.9t 2 + 340t ! 1278.4 = 0!!!!quadratic
2
!340 ± 340 2 ! (4 x 4.9 x ! 1278.4)
1
= 3.5757s!!!!!!!y = g(3.5757s)2 = 62.7m
2(4.9)
2
10.!(A)!sound!quality...look!at !your!notes
v
v
v
(B)!v = f ! !!! f = !!!beat ! frequency = fhigh " flow !!!!2.00Hz =
!"!
!
1.287m 1.297m
1.297m
1.297m!x! 2.0 s =
" v!!!!!!!v = 334 = 3.3!x!10 2 m s !!!!(C)!!see!your!notes
1.287m
I
"! %
!!!!!!I = \$ ! ' !10 x I o = (5.55)!10 x !i!1!x!10 (12
# 10 &
Io
12.!look!at !your!notes!
11.!(A)! ! = 10 log
W
m2
= !3.55!x!10 -7
W
m2
!!!!!(B)!look!at !your!notes!!!!!!!!!!!!!!!!!!!!!!!!!
1
v
340 m s
" !!!! " = 2l!!!!v = fo " !!!! fo = =
= 109.7 = 110Hz
2
" 2(1.55m)
v
340 m s
!!!!!(B)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!l = 2 " !!!! " = 0.5l!!!!!!! fo = =
= 439Hz
" 0.5(1.55m)
13.!(A)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!l !
14.!(A)!!v = f ! !!!! ! =
!(B)!T =
v
340 m s
=
= 0.276m !!
f 1255Hz
1
1
so x f = 1 the product!of!a!number!and!its!reciprocal!is!always!1!
f
f
15. (A) Look at your notes (B) Three are mentioned in the sound lab
(C) water... its denser
2(600m)
!(D)!(1)!double!the!distance!!!v =
= 1.4!x!10 3 m s !!!(2)!Doppler!shift!....the!fish!our!swimming!up
0.85s
16.!!!!!
f l'
F
D'
444Hz 2
1
.5
444Hz
=
x
x
!!!!!!
= x
x
!!!!!!! f ' !=
= 544Hz
'
'
'
f
l
f
1
0.816
D
3
1
F
17.!(A)!Brewster's!angle!(also!called!the!angle!of!polarization)
!!!!!(B)!!!tan ! p =
n2
n1
# 1.33 &
! p = tan "1 %
= 53.1o !!!!(C)!look!at!your!notes
\$ 1.00 ('
18.!I = 2! 2 f 2 "vao2 !!!!!ao =
I
=
2 2
2! f "
1!x!10 #10 mW2
= 2.15!x!10 -10 m
2! 2 (500Hz)2 (340 m s )1.29 kg m 3
19.!!v = f ! = f (4[l + 0.4d]) = 320Hz(4[0.252m + 0.4(0, 0285m)]) =! 337 m s
20.!!!!
h ' n1
=
h n2
!
5.00m 1.00
=
!!!!h = 6.65m
h
1.33
21. (A) it is a wave (B) either increase the wavelength or decrease the opening
22.!(A)!use!Snell's!law :!n1 sin !1 = n2 sin ! 2 1.00 sin 60.0 o = 2.42 sin ! rr!!!!!!!!!
!!!!!!! r = 21.0 o
c
c
c
(B)!n =
!!!!!!vdia = =
= 1.24!x!10 8 m s !!!!!(C)!!total!internal!reflection!&!dispersion
vdia
n 2.42
23. (A) longitudinal compression waves (B) primary... they are the first to arrive
v1 sin !1
5.0 km s sin 44.4 o
(D) look at your notes and lab
=
=
!!!!!!v2 = 4.15 m s
v2 sin ! 2
v2
sin 35.5 o
24. (A ) The orga n of Cor ti in t he coc hlea o f t he inner ear
(B) so un d is an i nver se sq uare la w, an d ear bu d s bei ng place d in the ear ca nal
po sitio ni ng t hem reall y clo se to t he i nner ear' s c hoc hlea
25. (A ) t he ocea n goe s fro m dee p wa ter to sh allo w wa ter (B) tow surfer in wit h a je t ski
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