Conceptual physics Exam Questions with Complete
Solutions
In simple harmonic motion, when is the speed the greatest? - Answer-when the
magnitude of the acceleration is a minimum
/.An object is attached to a vertical spring and bobs up and down between points A and
B. Where is the object located when its kinetic energy is a minimum? - Answer-at either
A or B
/.An object is attached to a vertical spring and bobs up and down between points A and
B. Where is the object located when its elastic potential energy is a minimum? -
Answer-midway between A and B
/.Two simple pendulums, A and B, are each 3.0 m long, and the period of pendulum A is
T. Pendulum A is twice as heavy as pendulum B. What is the period of pendulum B? -
Answer-T
/.The type of function that describes simple harmonic motion is what? - Answer-
sinusoidal
/.A mass is bobbing up and down on a spring. If you increase the amplitude of the
motion, how does this affect the time for one oscillation? - Answer-the time does not
change
/.If you drive an oscillator, it will have the largest amplitude if you drive it at its what
frequency? - Answer-resonant
/.A person's heart rate is given in beats per minute. Is this a period or a frequency? -
Answer-frequency
/.Flies flap their wings at frequencies much too high for pure muscle action. A
hypothesis for how they achieve these high frequencies is that the flapping of their
wings is the driven oscillation of a mass-spring system. One way to test this is to trim a
fly's wings. If the oscillation of the wings can be modeled as a mass-spring system, how
would this change the frequency of the wingbeats? - Answer-trimming the wings will
reduce their mass and this will increase the frequency of the wingbeats
/.Why does the intensity of waves from a small source decrease with the square of the
distance from the source? - Answer-the waves spread out as they travel
/.As you are moving very quickly toward a speaker emitting a pure tone, which
characteristics of the sound get larger? - Answer-loudness
, /.In many cartoon shows, a character runs off 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 foot of the cliff, the pitch of the
scream as he falls should be - Answer-higher than the original pitch and increasing as
he falls
/.Sound A has a high pitch and sound B has a low pitch. Which of the following
statements about these two sounds are correct? - Answer-the frequency of A is greater
than the frequency of B
/.When the particles of a medium move with simple harmonic motion, this means the
wave is what? - Answer-sinusoidal wave
/.Some bat species have auditory systems that work best over a narrow range of
frequencies. To account for this, the bats adjust the sound frequencies they emit so that
the returning, Doppler-shifted sound pulse is in the correct frequency range. As a bat
increases its forward speed, should it increase or decrease the frequency of the emitted
pulses to compensate? - Answer-the bat's forward motion means the reflected pulse will
be Doppler shifted to a higher frequency; consequently, the bat should decrease the
frequency of the emitted pulse so the reflected pulse will be in the correct frequency
range
/.In a resonating pipe that is open at both ends, there are what? - Answer-displacement
antinodes at each end
/.Consider the standing wave on a guitar string and the sound wave generated by the
string as a result of this vibration. What do these two waves have in common? -
Answer-they have the same frequency and the same speed
/.You can decrease the frequency of a standing wave on a string by doing what? -
Answer-decreasing the tension, making the string longer, or using a thicker string
/.If you pour liquid in a tall, narrow glass, you may hear sound with a steadily rising
pitch. What is the source of the sound, and why does the pitch rise as the glass fills? -
Answer-The sound you hear is the vibration of the glass; it is set into motion by the
disturbance of the flowing, sloshing liquid.
The disturbances are of many frequencies, but the natural frequency of the glass
resonates and is amplified by the glass while other frequencies are quickly damped out.
The reason the pitch rises as the glass fills is that the natural frequency of the glass
changes; as the glass fills the resonance frequency rises.
/.Certain illnesses inflame your vocal cords, causing them to swell. How does this affect
the pitch of your voice? - Answer-the frequency of the sound generated will decrease
/.If the index of refraction of a material is 2, this means that light travels how? - Answer-
2 times as fast in vacuum as it does in the material
Solutions
In simple harmonic motion, when is the speed the greatest? - Answer-when the
magnitude of the acceleration is a minimum
/.An object is attached to a vertical spring and bobs up and down between points A and
B. Where is the object located when its kinetic energy is a minimum? - Answer-at either
A or B
/.An object is attached to a vertical spring and bobs up and down between points A and
B. Where is the object located when its elastic potential energy is a minimum? -
Answer-midway between A and B
/.Two simple pendulums, A and B, are each 3.0 m long, and the period of pendulum A is
T. Pendulum A is twice as heavy as pendulum B. What is the period of pendulum B? -
Answer-T
/.The type of function that describes simple harmonic motion is what? - Answer-
sinusoidal
/.A mass is bobbing up and down on a spring. If you increase the amplitude of the
motion, how does this affect the time for one oscillation? - Answer-the time does not
change
/.If you drive an oscillator, it will have the largest amplitude if you drive it at its what
frequency? - Answer-resonant
/.A person's heart rate is given in beats per minute. Is this a period or a frequency? -
Answer-frequency
/.Flies flap their wings at frequencies much too high for pure muscle action. A
hypothesis for how they achieve these high frequencies is that the flapping of their
wings is the driven oscillation of a mass-spring system. One way to test this is to trim a
fly's wings. If the oscillation of the wings can be modeled as a mass-spring system, how
would this change the frequency of the wingbeats? - Answer-trimming the wings will
reduce their mass and this will increase the frequency of the wingbeats
/.Why does the intensity of waves from a small source decrease with the square of the
distance from the source? - Answer-the waves spread out as they travel
/.As you are moving very quickly toward a speaker emitting a pure tone, which
characteristics of the sound get larger? - Answer-loudness
, /.In many cartoon shows, a character runs off 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 foot of the cliff, the pitch of the
scream as he falls should be - Answer-higher than the original pitch and increasing as
he falls
/.Sound A has a high pitch and sound B has a low pitch. Which of the following
statements about these two sounds are correct? - Answer-the frequency of A is greater
than the frequency of B
/.When the particles of a medium move with simple harmonic motion, this means the
wave is what? - Answer-sinusoidal wave
/.Some bat species have auditory systems that work best over a narrow range of
frequencies. To account for this, the bats adjust the sound frequencies they emit so that
the returning, Doppler-shifted sound pulse is in the correct frequency range. As a bat
increases its forward speed, should it increase or decrease the frequency of the emitted
pulses to compensate? - Answer-the bat's forward motion means the reflected pulse will
be Doppler shifted to a higher frequency; consequently, the bat should decrease the
frequency of the emitted pulse so the reflected pulse will be in the correct frequency
range
/.In a resonating pipe that is open at both ends, there are what? - Answer-displacement
antinodes at each end
/.Consider the standing wave on a guitar string and the sound wave generated by the
string as a result of this vibration. What do these two waves have in common? -
Answer-they have the same frequency and the same speed
/.You can decrease the frequency of a standing wave on a string by doing what? -
Answer-decreasing the tension, making the string longer, or using a thicker string
/.If you pour liquid in a tall, narrow glass, you may hear sound with a steadily rising
pitch. What is the source of the sound, and why does the pitch rise as the glass fills? -
Answer-The sound you hear is the vibration of the glass; it is set into motion by the
disturbance of the flowing, sloshing liquid.
The disturbances are of many frequencies, but the natural frequency of the glass
resonates and is amplified by the glass while other frequencies are quickly damped out.
The reason the pitch rises as the glass fills is that the natural frequency of the glass
changes; as the glass fills the resonance frequency rises.
/.Certain illnesses inflame your vocal cords, causing them to swell. How does this affect
the pitch of your voice? - Answer-the frequency of the sound generated will decrease
/.If the index of refraction of a material is 2, this means that light travels how? - Answer-
2 times as fast in vacuum as it does in the material
