Page 1 of 7, February 21, 2015
Div B Crave The Wave, New Albany Invitational
Team #:
Science Olympiad
Crave The Wave
New Albany Invitational, February 21, 2015
INSTRUCTIONS
1. Turn in all exam materials at the end of this event.
2. Put your team name and number on EVERY page of the ANSWER SHEET and on the
cover of the exam packet in the upper right corner in the box provided.
3. Write your school name and individual names where indicated.
4. You may separate the exam pages. Re-clip them as you submit your materials to the
supervisor.
5. Provide the answers in the appropriate area on the ANSWER SHEET. Answers provided
outside the intended answer area may not be considered.
6. You are free to write anywhere in the packet, but only answers in the appropriate area
on the ANSWER SHEET will be counted.
7. Point values for each question are indicated on the ANSWER SHEET.
8. Tie Breakers: subscore on section 2, questions in reverse order on section 2, subscore
on section 1, questions in ascending number order on section 1.
9. You will be notified when it is your turn to visit the stations, if applicable. Please move
as quietly as possible so as to not disturb other teams.
10. When the time is up, the time is up. Continuing to write after the time is up risks
immediate disqualification.
Team Information
Team Name:
Name of Students:
Page 2 of 7, February 21, 2015
Div B Crave The Wave, New Albany Invitational
Team #:
Section One: Multiple Choice - Fill in the circle(s) fully and do not leave stray marks.
Note that some answers may require more than one selection to be filled in.
1. What are the primary colors of light?
A: Blue
B: Green
C: Yellow
D: Cyan
E: Red
2. What are the secondary colors of light?
A: Red
B: Cyan
C: Green
D: Yellow
E: Magenta
3. Relative to the angle of incidence, the angle of refraction
A: is smaller
B: is the same
C: is larger
4. In a vacuum, the speed of an electromagnetic wave
A: depends on its
B: depends on its
C: depends on its
frequency
wavelength
electric and magnetic
fields
5. Dispersion is the term used to describe
A: the splitting if white light B: the propagation of light
into its component colors
in straight lines
D: may be smaller, the same, or larger
D: is a universal
constant
C: the bending of a beam of
light when it goes from one
medium to another
E: depends on the
properties of its
medium
D: the bending of a beam of
light when it strikes a
mirror
6.
A medical imaging device produces ultrasound by oscillating with a period of 0.400 μs. What is the frequency of
this oscillation?
A: 2.5 Hz
B: 2500000 Hz
C: 0.4 Hz
D: 400 Hz
E: 24 Hz
7.
A string with both ends fixed produces a sound when plucked by virtue of a wave propagating along the string. It
has a certain frequency. What could be different about another string to make its sounds have a lower
frequency? Assume only one attribute would change at a time, but multiple aspects could yield the desired lower
frequency.
A: Increase the length
of the string
8.
C: Increase the
tension of the string
E: Increase the
density of the string
B: inverted
C: enlarged
D: left-right reversed
E: smaller
D: acceleration due
to gravity
E: the density of the
string
D: energy
E: wavelength
The speed of waves in a stretched string depends on
A: the tension in the
string
B: the amplitude of
the waves
C: The wavelength of
the waves
10. Waves transmit ______________ from one place to another.
A: mass
B: amplitude
C: particles
11.
D: Decrease the
tension of the string
When an object is reflected in a plane mirror, the image is always
A: real
9.
B: Decrease the
density of the string
Two excellent Science Olympiad students have a slinky stretched between them and are experimenting with
waves and have created a well-formed standing wave. They double the frequency of the wave—what happens?
A: the wavelength remains constant and the speed is
doubled to match the frequency
C: Both the wavelength and the speed are halved
B: The wavelength is halved and the speed remains the
same
E:
D: Fifth
BothClass
the wavelength and the speed remain the same
12. What are the regions of high pressure called in a sound wave?
A: crests
B: compressions
C: rarefactions
D: refractions
E: reflections
Page 3 of 7, February 21, 2015
13.
Div B Crave The Wave, New Albany Invitational
Team #:
The figure shows 3 layers of liquids, A, B, and C, each with a different
index of refraction. Light begins in liquid A, passes into B, and
eventually into C, as the ray of light in the drawing shows. The vertical
lines denote the normals to the interfaces between the layers. Which
liquid has the smallest index of refraction?
A: A
B: B
C: C
14.
The frequency of electromagnetic wave A is half that of electromagnetic wave B. For these two waves, what is
the ratio of the wavelengths λA to λB in a vacuum and why?
A: λA/λB = 2, because B: λA/λB = 2, because C: λA/λB = 1/2,
D: λA/λB = 1/2,
E: λA/λB = 1/2,
wave A has twice the both waves have the
because wave A has
because wave A has
because both waves
speed that wave B
same speed.
one-half the speed
twice the speed that
have the same speed.
has.
that wave B has.
wave B has.
15. The index of refraction of a material medium
A: is always less than B: is always equal to 1 C: is always greater
1
than 1
D: is always less than
0
16. Which of the following statements are true?
A: The speed of
B: The speed of
C: The speed of sound along a guitar string is
sound in air is
sound in air is
greater on a thicker string than on a thinner
greater in warm air
greater in cool air
string given that both strings are the same
than in cool air.
than in warm air.
length and are under the same tension
E: may be less than or
greater than 1
D: In general, sound travels
slowest in gases, faster in
solids, and fastest in liquids
17.
A piano tuner is testing middle A on the piano against a standard tuning fork with the exact frequency of 440 Hz.
She hears four beats per second, what are the possible frequencies of the piano chord?
A: 440 Hz
B: 444 Hz
C: 448 Hz
D: 432 Hz
E: 436 Hz
18.
A bat makes na ultrasonic wave for his echolocation that has a
wavelength of 8 mm. Given that the speed of sound is 343 m/s and
using the table shown as reference, which animals listed can hear
the bat’s echolocation wave?
A: dog
B: human
C: mouse
Animal
Range of hearing (Hz)
Elephant
Owl
Human
Dog
Mouse
Bat
Porpoise
<5 – 12,000
200-12,000
20-20,000
30-45,000
1000-90,000
2000-100,000
75-150,000
D: owl
E: porpoise
19. A radio station playing oldies calls itself “KOOL 105”. This means that they broadcast at 105 MHz. Support they
decided to describe they station by its broadcast wavelength (in meters) instead. What name would they use?
A: KOOL 0.35
B: KOOL 2.85
C: KOOL 3.5
D: KOOL 285
E: KOOL 350
20. A wave has amplitude of 6.0 cm and a frequency of 10 Hz, and the distance from a crest to the nearest trough
(measured along the direction of the wave’s energy transfer) is measured to be 4.0 cm. Determine the period of
such a wave.
A: 60 s
B: 1.5 s
C: 0.4 s
D: 0.1 s
E: 4 s
Page 4 of 7, February 21, 2015
Div B Crave The Wave, New Albany Invitational
Team #:
21. The drawing shows a 30-60-90 prism and 2 light rays, A and B, both
of which strike the prism perpendicularly. The prism is surrounded
by an unknown liquid. When ray A reaches the hypotenuse in the
drawing, it is totally internally reflected. Which one of the
following statements applies to ray B when it reaches the
hypotenuse?
A: It may or may not be totally
internally reflected, depending on
what the surrounding liquid is
B: It is totally internally reflected, no
matter what the surrounding liquid is.
C: It is not totally internally reflected, no
matter what the surrounding liquid is
22. What types of EM Radiation have a lower frequency than Ultraviolet rays?
A: Visible light
B: Microwaves
C: Gamma rays
D: X-rays
E: radio waves
23. Comparing two different types of electromagnetic waves, infrared and ultraviolet, we can say that
A: Infrared has a longer
wavelength and higher
frequency than ultraviolet
B: Infrared has a shorter
wavelength and higher
frequency than ultraviolet
C: Infrared has a longer
wavelength and lower
frequency than ultraviolet
D: Infrared has a shorter
wavelength and lower
frequency than ultraviolet
24. What type of waves are absorbed by molecules that have a dipole moment in liquids?
A: visible light waves
B: gamma-rays
C: x-rays
D: infrared waves
E: microwaves
25. __________ radiation is electromagnetic radiation emitted when a charged passes through a dielectric medium at
a speed greater than the phase velocity of light in that medium.
A: Fourier
B: Lorentz
C: Einstein
D: Planck
E: Cherenkov
26. What is the frequency of blue light with a wavelength of 400 nm?
A: 1.33 x 103 Hz
B: 7.50 x 1012 Hz
C: 1.33 x 1012 Hz
D: 7.50 x 1014 Hz
27. How many times more intense is a 90 dB sound than a 40 dB sound?
A: 5
B: 50
C: 500
D: 5000
E: 1.33 x 1014 Hz
E: 105
28. The wave speed on a string under tension is 200 m/s. What is the speed if the tension is doubled?
A: 200 m/s
B: 280 m/s
C: 400 m/s
D: 100 m/s
E: 800 m/s
29. __________ is the phenomenon of a wave changing its speed
A: refraction
B: polarization
C: interference
D: diffraction
E: dispersion
30. An organ pipe is tuned to exactly 384 Hz when the temperature in the room is 20° C. Later, when the room was
warmed up to 25° C, the frequency is
A: Greater than 384 Hz
B: 384 Hz
C: Less than 384 Hz
31. The higher the frequency of a wave,
A: the lower its speed
B: the shorter its
wavelength
C: the greater its
amplitude
D: the longer its
period
E: the longer its
wavelength
32. Of the following properties of a wave, the one that is independent of the others is its
A: amplitude
B: wavelength
C: speed
D: period
E: frequency
Page 5 of 7, February 21, 2015
Div B Crave The Wave, New Albany Invitational
Team #:
33. In a transverse wave, the individual particles of the medium move
A: in circles
B: in ellipses
C: parallel to the direction
of travel
D: perpendicular to the
direction of travel
34. Sound waves are
A: longitudinal
B: transvers
C: torsional
D: partly longitudinal and partly transverse
35. The amplitude of a sound wave determines its
A: pitch
B: overtones
C: loudness
D: resonance
E: timbre
36. A pure musical tone causes a thin wooden panel to vibrate. This is an example of
A: an overtone
B: harmonics
C: resonance
D: diffraction
E: refraction
37. When a sound wave goes from air into water, the quantity that remains unchanged is its
A: speed
B: amplitude
C: frequency
D: wavelength
38. The frequency of the lowest standing-wave mode on a 1.0 m long string is 20 Hz. What is the wave speed on the
string?
A: 10 m/s
B: 20 m/s
C: 30 m/s
D: 40 m/s
E: 50 m/s
39. You look at yourself in a convex mirror. Your image is
A: upright
B: inverted
C: impossible to tell without knowing how far you are from the mirror and its focal length
40. In a darkened room, red light shines on a red cup, a white card, and a blue toy. The cup, card, and toy will appear,
respectively
A: red, red, blue
B: red, white, blue
C: red, red, black
D: red, black, blue
E: red, red, red
Section Two: Problems to Solve. Please show your work and answer clearly on the answer sheet. Full credit
will only be given if your work is shown.
1.
An ocean wave has a wavelength of 111 m and a period of 2.2 s.
a) What is the frequency of the wave?
b) What is the speed of the wave?
2.
How far does light travel in a leap year? (in meters, use scientific notation)
3.
The index of refraction of crown glass for red light is 1.51 and for violet light is 1.53. A beam of white light falls on
a cube of such glass at an incident angle of 40°. What is the difference between the angles of refraction of the red
and violet light?
Page 6 of 7, February 21, 2015
Div B Crave The Wave, New Albany Invitational
Team #:
4.
Compression waves (sound waves) are sent down an air-filled tube 75.0 cm long and closed at one end. The tube
resonates at several frequencies, the lowest of which is 121 Hz.
a) Find the speed of sound waves in air.
b) Find the 1st overtone (3rd harmonic) (next resonant frequency).
c) Find the 2nd overtone (5th harmonic) (next resonant frequency).
5.
As is drawn in the figure, a ray of light in air strikes a
glass plate (n = 1.50) at an incidence angle of 50°.
a. Determine the angle between the reflected
and refracted ray.
6.
A transparent solid is given to you, but you do not
know what it is. One way to identify the substance
would be to measure the critical angle when the
solid is in air. A list of materials and their index of
refraction values is provided. If the critical angle is
measured to be 24.4 degrees, what material were
you given?
7.
A motorist goes through a red light and, when he is arrested, claims that the color he actually saw was green (λ =
5.4 x 10-7 m) and not red (λ = 6.2 x 10-7 m) because of the Doppler shift. The judge accepts this explanation and
instead fines him of speeding at $1 for each km/hr that he exceeded the speed limit of 80 km/hr. What was his
fine?
Page 7 of 7, February 21, 2015
Div B Crave The Wave, New Albany Invitational
Team #:
8.
The speed of a transverse wave on a string is 500.0 m/s, and the wavelength is 0.25 m. The amplitude of the wave
is 0.75 cm. How much time is required for a particle of the string to move through a total distance of 3.0 km?
9.
Four spectra for some elements
common in the atmospheres of
stars are provided to the right:
a.
What elements are
present in this star’s
spectra?
b. What elements are
present in this star’s
spectra?