Sound vibrations with frequencies greater than 20,000 Hz are called
A) megasonics.
B) infrared
C) supersonics
D) ultrasonics
E) infrasonics
What happens to a simple pendulumʹs frequency if both its length and mass are increased?
A) It increases
B) It remains constant.
C) It decreases.
D) It could remain constant, increase, or decrease; it depends on the mass to length ratio (mass density)
What is the amplitude (in meters) of a wave whose displacement is given by y = 50. sin(0.20x + 120t) cm?
A) 6 m
B) 10 m
C) 1.0 m
D) 0.50 m
E) 0.20 m
What happens to the velocity of sound in a gas when the absolute temperature of that gas is doubled?
A) It doubles.
B) It stays the same.
C) It increases to 1.41 times its original value
D) It quadruples.
Simple Harmonic Motion is characterized by
A) acceleration proportional to the acceleration of gravity
B) acceleration proportional to displacement.
C) acceleration proportional to velocity.
D) constant acceleration
E) acceleration inversely proportional to velocity.
Several electrons are placed on a hollow metal sphere. They
A) clump together on the sphereʹs inner surface.
B) become uniformly distributed on the sphereʹs inner surface
C) become uniformly distributed on the sphereʹs outer surface
D) clump together on the sphereʹs outer surface.
8) Fig. 15-5 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have an electric flux of +q/εo through them?
A) a
B) b.
C) c
D) b and d
E) b and c
When a wave obliquely crosses a boundary into another medium, it is
A) diffracted.
B) always slowed down
C) reflected
D) refracted
E) always speeded up
A sound source departs from a stationary observer. The frequency heard by the observer is
A) higher than the source.
B) equal to zero
C) lower than the source
D) the same as that of the source
E) impossible to predict
A car approaches you at a constant speed, sounding its horn, and you hear a frequency of 76 Hz. After the car goes by, you hear a frequency of 65 Hz. What is the frequency of the sound emitted by the horn? The speed of sound in air is 343 m/s
A) 71 Hz
B) 72 Hz
C) 68 Hz
D) 69 Hz
E) 70 Hz
A mass swinging on the end of a massless string, as shown in Fig. 13-2, undergoes SHM. Where is the instantaneous acceleration of the mass greatest?
A) A and D
B) A and C
C) B
D) C
E) A and B
Compared to the wavelength of a 400 Hz sound, the wavelength of a 200 Hz sound in air is
A) twice as long
B) four times as long
C) the same
D) one-half as long
E) none of the above
A closed organ pipe of length 0.750 m is played when the speed of sound in air is 340. m/s. What is the fundamental frequency?
A) 171. Hz
B) 0.228 kHz
C) 57.0 Hz
D) 570. Hz
E) 0.113 kHz
A mass is attached to a spring of spring constant 60 N/m along a horizontal, frictionless surface. The spring is initially stretched by a force of 5.0 N on the mass and let go. It takes the mass 0.50 s to go back to its equilibrium position when it is oscillating. What is the period of oscillation?
A) 1.0 s
B) 1.5 s
C) 2.0 s
D) 2.5 s
E) 0.50 s
Two coherent sound waves will destructively interfere when the path difference is the wavelength times what?
A) an odd integer
B) half an odd integer
C) an integer
D) half an even integer
As shown in Fig. 15-1, a point charge of +Q is placed at the centroid of an equilateral triangle. When a second charge of +Q is placed at one of the triangleʹs vertices, an electrostatic force of 4.0 N acts on it. What is the magnitude of the force that acts on the center charge due to a third charge of +Q placed at one of the other vertices?
A) 4.0 N
B) 16 N
C) 2.0 N
D) 8.0 N
E) zero
When an electron is removed from a neutral atom, it becomes
A) a bipolar atom
B) more massive
C) heavier
D) a negative ion
E) a positive ion
A metal sphere of radius 10 cm carries a charge of +2.0 μC. What is the magnitude of the electric field 5.0 cm outside the sphereʹs surface?
A) 8.0 × 10^7 N/C
B) 4.0 × 10^5 N/C
C) 4.0 × 10^7 N/C
D) 4.2 × 10^6 N/C
E) 8.0 × 10^5 N/C
Compare two vibrating strings, each has the same tension, but the second has four times the mass density of the first. The wave speed along the 2nd string is how many times the speed along the 1st?
A) 1/2
B) 4
C) 1/4
D) 2
E) Sqrt 2
The half angle of the conical shock wave produced by a supersonic aircraft is 60 °. What is the Mach number of the aircraft
A) 1.73
B) 1.15
C) Sqrt 2
D) 0.87
E) 2.0
Which part of a vibrating string experiences the maximum acceleration
A) nodes
B) antinodes
C) ends
The decibel level of sound is related to its
A) pitch
B) intensity
C) wavelength
D) frequency
E) velocity
What is the speed of sound in air at freezing temperature?
A) 1100 m/s
B) 331 m/s
C) 650 mph
D) 650 m/s
E) 331 mph
Consider the wave shown in Fig. 13-4. The amplitude
A) is 1 m.
B) is 4 m.
C) is 8 m.
D) is 2 m.
E) cannot be determined from given information
The wavelength in Fig. 13-
A) is 4 m
B) is 8 m
C) is 2 m
D) is 1 m
E) cannot be determined from the given information
If the intensity of sound changes (increases) by a factor of 100, the decibel level changes by a factor of
A) 100
B) 20
C) 10
D) 1
E) log 100
Which of the following is an accurate statement?
A) If a solid metal sphere carries a net charge, the charge will move to the sphere surface.
B) If a solid metal sphere carries a net charge, the charge will be uniformly distributed throughout the volume of the sphere.
C) The electric field at the surface of a conductor is not necessarily perpendicular to the surface in all cases.
D) A conductor cannot carry a net charge.
A simple pendulum consists of a mass M attached to a weightless string of length L. For this system, when undergoing small oscillations
A) the frequency is independent of the length L
B) the frequency is proportional to the amplitude
C) the frequency is independent of the mass M
D) the frequency is proportional to the period
E) the period is proportional to the amplitude
In a resonating pipe which is open at one end and closed at the other, there
A) is a displacement node at the open end and a displacement antinode at the closed end
B) are displacement nodes at each end.
C) are displacement antinodes at each end.
D) is a displacement node at the closed end and a displacement antinode at the open end
The main difference between conductors and insulators is in terms of
A) atoms.
B) protons.
C) neutrons
D) valence or conduction electrons.
E) None of the other choices is correct
Fig. 15.5 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have no electric flux through them?
A) a.
B) b
C) b and c
D) b and d
E) c
The total energy stored in simple harmonic motion is proportional to the
A) frequency of motion
B) square of the amplitude
C) amplitude
D) reciprocal of the spring constant
E) square of the spring constant
The total distance traveled by an object in one complete cycle of Simple Harmonic Motion is ________ times the amplitude.
A) two
B) one
C) three
D) half
E) four
In music the 3rd harmonic is which overtone?
A) 4th
B) 5th
C) 1st
D) 2nd
E) 3rd
Consider an open pipe of length L. What are the wavelengths of the three lowest tones produced by this pipe?
A) 4L, 4L/3, 4L/5
B) 2L, L, 2L/3
C) 4L, 2L, L
D) 2L, L, L/2
An electron and a proton are separated by a distance of 1 m. What happens to the size of the force on the proton if the electron is moved 0.5 m closer to the proton?
A) It increases to 2 times its original value
B) It increases to 8 times its original value
C) It increases to 4 times its original value
D) It decreases to one-fourth its original value
E) It decreases to one-half its original value
Grandfather clocks often are built so that each one-way swing of the pendulum is a second. How long is the length of a simple pendulum for a 2.00 second period?
A) 24.8 cm
B) 0.500 m
C) 500. cm
D) 0.993 m
E) 101.cm
One of the harmonics of a string fixed at both ends has a frequency of 52.2 Hz and the next higher harmonic has a frequency of 60.9 Hz. What is the fundamental frequency of the string?
A) 17.4 Hz
B) 30.4 Hz
C) 26.1 Hz
D) 8.7 Hz
E) 4.35 Hz
In electricity, what quantity is analogous to the ʺacceleration of gravityʺ g (which is a force per unit mass)?
A) electric charge
B) electric force
C) electric potential
D) electric field
E) an electric dipole
Electric field lines
A) were discovered by Franklin.
B) are closer together the stronger the field.
C) start on negative charges and end on positive charges
D) are perpendicular to the lines of force
E) were invented by Isaac Newton.
) In many cartoon shows, a character runs of a cliff, realizes his predicament and lets out a scream. He continues to scream as he falls. If the physical situation is portrayed correctly, from the vantage point of an observer at the top of the cliff leaning over the edge, the pitch of the scream should be
A) lower than the original pitch and decreasing as he falls.
B) higher than the original pitch and increasing as he falls.
C) higher than the original pitch and constant.
D) lower than the original pitch and constant.
E) It is impossible to predict.
The reason that you do not observe a Doppler shift when you listen to the car radio while driving is that
A) the source and observer are moving at the same speed
B) there is a Doppler shift but we donʹt notice it.
C) the speed of the car is too slow compared to the speed of sound
D) the air inside the car is moving at the same speed as the car
E) the speed of the car is too fast compared to the speed of sound
A string of linear density 1.5 g/m is under a tension of 20. N. What should its length be if its fundamental resonance frequency is 220. Hz?
A) 43. cm
B) 1.1 m
C) 0.96 m
D) 2.1 m
E) 0.26 m
Which of the arrows shown in Figure 19-12 represents the correct direction of the electric field between the two metal plates?
A) A
B) B
C) C
D) D
E) none of the abovw
Three point charges are located at the following positions: Q1 = 2.00 μC at x = 1.00 m; Q2 = 3.00 μC at x = 0; Q3 = -5.00 μC at x = -1.00 m. What is the magnitude of the force on the 3.00-μC charge?
A) 0.158 N
B) 0.189 N
C) 8.10 × 10-2 N
D) 0.135 N
E) 5.40 × 10-2 N
The electric field shown in Fig. 15-3
A) decreases down
B) decreases to the right
C) is uniform
D) increases to the right.
E) increases down
Doubling only the amplitude of a vibrating mass-and-spring system produces what effect on the systemʹs mechanical energy?
A) increases the energy by a factor of four
B) increases the energy by a factor of two
C) increases the energy by a factor of Sqrt 2
D) increases the energy by a factor of three
E) produces no change
When waves interfere, the result is ________ original waves (ʺthey interfereʺ)
A) always smaller than
B) sometimes smaller than, sometimes larger than
C) always the same as
D) always larger than
If you take a given pendulum to the moon, where the acceleration of gravity is less than on Earth, the resonant frequency of the pendulum will
A) not change.
B) increase.
C) decrease.
D) either increase or decrease; it depends on its length to mass ratio
Fig. 15-8 shows electric field lines near two electric point charges. If Q1 = -1 μC, what is the value of Q2?
A) +1 μC
B) +2 μC
C) 0
D) -1 μC
E) -2 μC
Sound intensity is defined as
A) the sound energy passing through a unit of area per unit time
B) the sound power per unit volume
C) the loudness of a sound
D) the sound energy passing through a unit of area
E) the sound power per unit time
Three point charges each equal to 10 microcoulombs are located at x = 1m, x = 2m, and x = 3m, respectively, on the x-axis. What is the magnitude of the electric field at the origin?
A) 1.22 × 10^5 N/C
B) 2.25 × 10^3 N/C
C) 1.65 × 10^4 N/C
D) 1.75 × 10^6 N/C
E) 2.70 × 10^4 N/C
A factory siren indicating the end of a shift has a frequency of 80 Hz. What frequency is perceived by the occupant of a car traveling towards the factory at 30 m/s? The speed of sound in air is 343 m/s
A) 87 Hz
B) 83 Hz
C) 89 Hz
D) 91 Hz
E) 85 Hz
If one doubles the tension in a violin string, the fundamental frequency of that string will be how many times the original frequency?
A) 2
B) 4
C) 2^3
D) Sqrt 2
E) 1/ Sqrt 2
A sound source approaches a stationary observer. The frequency heard by the observer is
A) the same as that of the source
B) higher than the source
C) equal to zero
D) lower than the source
E) impossible to predict
What is the frequency (in Hz) of a wave whose displacement is given y = 50. sin(0.20x + 120t), where x and y are in cm and t in seconds?
A) 120 Sqrt 2π H
B) 0.120 kHz
C) 0.5 Hz
D) 10 Hz
E) 19. Hz
What are the magnitude and direction of the electric field at a distance of 1.50 m from a 50.0-nC charge?
A) 10 N/C away from the charge
B) 200 N/C away from the charge
C) 20 N/C away from the charge
D) 200 N/C toward the charge
E) 20 N/C toward the charge
A mass vibrates back and forth from the free end of an ideal spring (k = 20. N/m) with an amplitude of 0.25 m. What is the maximum kinetic energy of this vibrating mass
A) 0.63 J
B) 1.3 J
C) 2.5 J
D) 5.0 J
E) It is impossible to give an answer since kinetic energy cannot be determined without knowing the objectʹs mass.
The frequency in Fig. 13-4
A) is 0.5 Hz.
B) is 4 Hz.
C) is 1 Hz
D) is 2 Hz
E) cannot be determined from the given information