PHYS 202 - Reading Questions

A compression in a sound wave is a region where A. the density is higher than average. B. the pressure is higher than average. C. the air molecules are closer together than average.

All of the above

Which has the greater density, 7 g of mercury or 1000 g of water?

7g mercury

A simple pendulum consisting of a bob of mass m attached to a string of length L swings with a period T. If the bob's mass is doubled, approximately what will the pendulum's new period be? A. T/2 B. T C. 2√T D. 2T

B. T

If the frequency is 40 Hz, what is the period T ?

0.025s

An oscillating object takes 0.10 s to complete one cycle; that is, its period is 0.10 s. What is its frequency f?

10 Hz

An oscillator creates periodic waves on two strings made of the same material. The tension is the same in both strings. If the strings have different thicknesses, which of the following parameters, if any, will be different in the two strings? A. wave frequency B. wave speed C. wavelength D. none of the above

B and C

How many times more intense is a 100 dB sound compared to a 50 dB sound? A. 2 times B. 50 times C. 1000 times D. 5000 times E. 100,000 times

E. 100,000 times ( Δβ =50⇒I2/I1=10^50/10=10^5)

Sound waves in air are A. transverse waves B. longitudinal waves

B. longitudinal waves

A certain sound is recorded by a microphone. The same microphone then detects a second sound, which is identical to the first one except that it has twice the frequency. In addition to the higher frequency, what distinguishes the second sound from the first one? A. It is perceived as higher in pitch. B. It is perceived as louder. C. It has a higher amplitude. D. It has a longer wavelength.

A. It is perceived as higher in pitch.

As a sound wave spreads out from a point source its intensity decreases because A. The surface area over which it acts increases. B. Its power increases. C. The surface area over which it acts decreases. D. Its power decreases.

A. The surface area over which it acts increases

A 100 Hz sound wave is traveling through the air. If we increase the frequency to 200 Hz, this will _____ the wavelength. A. decrease B. not change C. increase

A. decrease

The magnitude of the buoyant force is equal to the weight of fluid displaced by the object. Under what circumstances is this statement true? A. for every object submerged partially or completely in a fluid B. only for an object that floats C. only for an object that sinks D. for no object submerged in a fluid

A. for every object submerged partially or completely in a fluid

A source producing sound at a frequency of 1000 Hz moves towards Nancy and away from Pablo. Nancy hears the sound at a frequency A. greater than 1000 Hz. B. of 1000 Hz. C. less than 1000 Hz.

A. greater than 1000 Hz.

When two waves overlap, the displacement of the medium is the sum of the displacements of the two individual waves. This is the principle of __________. A. superposition B. standing waves C. constructive interference D. destructive interference

A. superposition

A shock wave is produced A. when the source of a wave travels faster than the speed of the wave. B. only when an airplane travels faster than the speed of sound. C. when a wave travels faster than its source.

A. when the source of a wave travels faster than the speed of the wave.

Does air play a role in the propagation of the human voice from one end of a lecture hall to the other? A. yes B. no

A. yes

A certain sound is recorded by a microphone. The same microphone then detects a second sound, which is identical to the first one except that the amplitude of the pressure fluctuations is larger. In addition to the larger amplitude, what distinguishes the second sound from the first one? A. It is perceived as higher in pitch. B. It is perceived as louder. C. It has a higher frequency. D. It has a longer wavelength.

B. It is perceived as louder.

Two objects, T and B, have identical size and shape and have uniform density. They are carefully placed in a container filled with a liquid. Both objects float in equilibrium. Less of object T is submerged than of object B, which floats, fully submerged, closer to the bottom of the container. Which of the following statements is true? A. Object T has a greater density than object B. B. Object B has a greater density than object T. C. Both objects have the same density.

B. Object B has a greater density than object T.

The pressure at 10 m below the surface of the ocean is about 2.00×105 Pa .Which of the following statements is true? A. The weight of a column of seawater 1 m2 in cross section and 10 m high is about 2.00×105 N. B. The weight of a column of seawater 1 m2 in cross section and 10 m high plus the weight of a column of air with the same cross section extending up to the top of the atmosphere is about 2.00×105 N. C. The weight of 1 m3 of seawater at 10 m below the surface of the ocean is about 2.00×105 N. D. The density of seawater is about 2.00×105 times the density of air at sea level.

B. The weight of a column of seawater 1 m2 in cross section and 10 m high plus the weight of a column of air with the same cross section extending up to the top of the atmosphere is about 2.00×105 N.

In (Figure 1), is pA larger, smaller, or equal to pB? Choose the correct explanation. A. The ship is lighter that the water since it doesn't go down. Point A has to support the weight of the ship, while point B has to support the water. pA<pB. B. Two points on a horizontal line, connected by a single liquid in hydrostatic equilibrium, are at the same pressure. pA=pB. C. Point A has to support the weight of the ship, while point B does not. pA>pB. D. Two points on any line, connected by a single liquid in hydrostatic equilibrium, are at the same pressure. pA=pB.

B. Two points on a horizontal line, connected by a single liquid in hydrostatic equilibrium, are at the same pressure. pA=pB.

The magnitude of the buoyant force equals the weight of the object. Under what circumstances is this statement true? A. for every object submerged partially or completely in a fluid B. for an object that floats C. only for an object that sinks D. for no object submerged in a fluid

B. for an object that floats

A stationary source emits sound at a frequency of 1000 Hz. Pablo is moving toward the source and Nancy is moving away from the source. Nancy hears the sound at a frequency A. of 1000 Hz. B. less than 1000 Hz. C. greater than 1000 Hz.

B. less than 1000 Hz.

A point on a standing wave that is always stationary is a(n) _____. A. minimum B. node C. maximum D. antinode

B. node

We describe sound waves in terms of pressure. Given this, for a standing wave in a tube open at each end, the open ends of the tube are __________. A. neither nodes or antinodes B. nodes C. antinodes

B. nodes

If you want to play a tune on wine glasses, you'll need to adjust the oscillation frequencies by adding water to the glasses. This changes the mass that oscillates (more water means more mass) but not the restoring force, which is determined by the stiffness of the glass itself. If you need to raise the frequency of a particular glass, should you add water or remove water? A. Add water B. Remove water

B. remove water

What varies between two tones that are different in timbre, that is, two tones that have the same fundamental frequency but are produced, say, by different musical instruments? A. the pitch B. the harmonic content C. nothing

B. the harmonic content

A simple pendulum consisting of a bob of mass m attached to a string of length L swings with a period T. If the pendulum is brought on the moon where the gravitational acceleration is about g/6, approximately what will its period now be? A. T/6 B. T/6√ C. 6√T D. 6T

C. 6√T

A simple pendulum consisting of a bob of mass m attached to a string of length L swings with a period T. If the pendulum is taken into the orbiting space station what will happen to the bob? A. It will continue to oscillate in a vertical plane with the same period. B. It will no longer oscillate because there is no gravity in space. C. It will no longer oscillate because both the pendulum and the point to which it is attached are in free fall. D. It will oscillate much faster with a period that approaches zero. Submit

C. It will no longer oscillate because both the pendulum and the point to which it is attached are in free fall.

Having established that a sound wave corresponds to pressure fluctuations in the medium, what can you conclude about the direction in which such pressure fluctuations travel? A. The direction of motion of pressure fluctuations is independent of the direction of motion of the sound wave. B. Pressure fluctuations travel perpendicularly to the direction of propagation of the sound wave. C. Pressure fluctuations travel along the direction of propagation of the sound wave.

C. Pressure fluctuations travel along the direction of propagation of the sound wave.

Based on the information presented in the introduction of this problem, what is a sound wave? A. Propagation of sound particles that are different from the particles that comprise the medium B. Propagation of energy that does not require a medium C. Propagation of pressure fluctuations in a medium D. Propagation of energy that passes through empty spaces between the particles that comprise the medium

C. Propagation of pressure fluctuations in a medium

An object is floating in equilibrium on the surface of a liquid. The object is then removed and placed in another container, filled with a denser liquid. What would you observe? A. The object would sink all the way to the bottom. B. The object would float submerged more deeply than in the first container. C. The object would float submerged less deeply than in the first container. D. More than one of these outcomes is possible.

C. The object would float submerged less deeply than in the first container.

The pressure at 10 m below the surface of the ocean is about 2.00×105 Pa .Now consider the pressure 20 m below the surface of the ocean. Which of the following statements is true? A. The pressure is twice that at a depth of 10 m. B. The pressure is the same as that at a depth of 10 m. C. The pressure is equal to that at a depth of 10 m plus the weight per 1 m2 cross sectional area of a column of seawater 10 m high. D. The pressure is equal to the weight per 1 m2 cross sectional area of a column of seawater 20 m high.

C. The pressure is equal to that at a depth of 10 m plus the weight per 1 m2 cross sectional area of a column of seawater 10 m high.

The interference of two sound waves of similar amplitude but slightly different frequencies produces a loud-soft-loud oscillation we call __________. A. the Doppler effect B. constructive and destructive interference C. beats D. vibrato

C. beats

The magnitude of the buoyant force is equal to the weight of the amount of fluid that has the same total volume as the object. Under what circumstances is this statement true? A. for an object that is partially submerged in a fluid B. only for an object that floats C. for an object completely submerged in a fluid D. for no object partially or completely submerged in a fluid

C. for an object completely submerged in a fluid

The magnitude of the buoyant force is less than the weight of the object. Under what circumstances is this statement true? A. for every object submerged partially or completely in a fluid B. for an object that floats C. for an object that sinks D. for no object submerged in a fluid

C. for an object that sinks

A stationary source emits sound at a frequency of 1000 Hz. Pablo is moving toward the source and Nancy is moving away from the source. Pablo hears the sound at a frequency A. of 1000 Hz. B. less than 1000 Hz. C. greater than 1000 Hz.

C. greater than 1000 Hz.

If the period is doubled, the frequency is A. unchanged. B. doubled. C. halved.

C. halved

A source producing sound at a frequency of 1000 Hz moves towards Nancy and away from Pablo. Pablo hears the sound at a frequency A. greater than 1000 Hz. B. of 1000 Hz. C. less than 1000 Hz.

C. less than 1000 Hz.

If you drive an oscillator, it will have the largest amplitude if you drive it at its _______ frequency. A. pendulum B. damped C. resonant D. special E. positive

C. resonant

You can decrease the frequency of a standing wave on a string by __________. A. making the string longer B. using a thicker string C. decreasing the tension D. All of the listed answers are correct.

D. All of the listed answers are correct.

An object is floating in equilibrium on the surface of a liquid. The object is then removed and placed in another container, filled with a less dense liquid. What would you observe? A. The object would sink all the way to the bottom. B. The object would float submerged more deeply than in the first container. C. The object would float submerged less deeply than in the first container. D. More than one of these outcomes is possible.

D. More than one of these outcomes is possible.

Consider a block of mass m attached to a spring with force constant k, as shown in the figure(Figure 1). The spring can be either stretched or compressed. The block slides on a frictionless horizontal surface, as shown. When the spring is relaxed, the block is located at x=0. If the block is pulled to the right a distance A and then released, A will be the amplitude of the resulting oscillations. After the block is released from x=A, it will A. remain at rest. B. move to the left until it reaches equilibrium and stop there. C. move to the left until it reaches x=−A and stop there. D. move to the left until it reaches x=−A and then begin to move to the right.

D. move to the left until it reaches x=−A and then begin to move to the right.

An oscillator creates periodic waves on two strings made of the same material. The tension is the same in both strings. If the strings have the same thickness but different lengths, which of the following parameters, if any, will be different in the two strings? A. wave frequency B. wave speed C. wavelength D. none of the above

D. none of the above