This
printout
should
have
14
questions.
Multiplechoice questions may continue on
the next column or page – fnd all choices
beFore answering.
001
(part 1 oF 3) 10.0 points
Two waves in one string are described by the
relationships
y
1
=
A
1
cos(
k
1
x

ω
1
t
)
y
2
=
A
2
sin(
k
2
x

ω
2
t
)
where
A
1
= 4
.
8 cm,
A
2
= 3
.
4 cm,
k
1
=
4
cm
−
1
,
k
2
=
2
cm
−
1
,
ω
1
=
1
rad
/
s,
ω
2
= 3 rad
/
s,
y
and
x
are in centimeters,
and
t
is in seconds.
±ind the superposition oF the waves at the
position 2 cm and time 0
.
7 s.
Correct answer: 5
.
74259 cm.
Explanation:
Let :
x
1
= 2 cm
and
t
1
= 0
.
7 s
.
At this point we have
y
1
= (4
.
8 cm) cos
b
(4 cm
−
1
) (2 cm)

(1 rad
/
s) (0
.
7 s)
B
= 2
.
52517 cm
and
y
2
= (3
.
4 cm) sin
b
(2 cm
−
1
) (2 cm)

(3 rad
/
s) (0
.
7 s)
B
= 3
.
21742 cm
,
so
y
1
+
y
2
=
5
.
74259 cm
.
002
(part 2 oF 3) 10.0 points
±ind the superposition oF the waves
y
1
+
y
2
at
the position 1 cm and time 0
.
8 s.
Correct answer:

6
.
11584 cm.
Explanation:
Let :
x
2
= 1 cm
and
t
2
= 0
.
8 s
.
At this point we have
y
1
= (4
.
8 cm) cos
b
(4 cm
−
1
) (1 cm)

(1 rad
/
s) (0
.
8 s)
B
=

4
.
79181 cm
and
y
2
= (3
.
4 cm) sin
b
(2 cm
−
1
) (1 cm)

(3 rad
/
s) (0
.
8 s)
B
=

1
.
32402 cm
,
so
y
1
+
y
2
=

6
.
11584 cm
.
003
(part 3 oF 3) 10.0 points
±ind the superposition oF the waves
y
1
+
y
2
at
the position 0
.
7 cm and time 21 s.
Correct answer: 7
.
02905 cm.
Explanation:
Let :
x
3
= 0
.
7 cm
and
t
3
= 21 s
.
At this point we have
y
1
= (4
.
8 cm) cos
b
(4 cm
−
1
) (0
.
7 cm)

(1 rad
/
s) (21 s)
B
= 3
.
82249 cm
and
y
2
= (3
.
4 cm) sin
b
(2 cm
−
1
) (0
.
7 cm)

(3 rad
/
s) (21 s)
B
= 3
.
20656 cm
,
so
y
1
+
y
2
=
7
.
02905 cm
.
004
10.0 points
The distance between two successive maxima
oF a certain transverse wave is 1
.
86 m. Eight
crests, or maxima, pass a given point along
the direction oF travel every 17
.
4 s.
Calculate the wave speed.
Correct answer: 0
.
855172 m
/
s.
oldhomework 38 – Turner – (58185)
1
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Documenthinojosa (jlh3938) – oldhomework 38 – Turner – (58185)
2
Explanation:
Let :
λ
= 1
.
86 m
,
t
= 17
.
4 s
,
and
n
= 8
.
The frequency of the transverse wave is
f
=
n
t
=
8
17
.
4 s
= 0
.
45977 Hz
.
The wave speed then is
v
=
λ f
= (1
.
86 m)(0
.
45977 Hz)
=
0
.
855172 m
/
s
.
005
(part 1 of 3) 10.0 points
The time needed for a water wave to change
from the equilibrium level to the crest is
0
.
1775 s.
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '08
 Turner
 Work, Sin, Correct Answer, Hinojosa

Click to edit the document details