Question 1

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?

Accepted Answer

The elastic potential energy of an object attached to a spring is minimum when the spring is neither stretched nor compressed, which occurs at the equilibrium position. This position is midway between the two extremes of the motion (points A and B), where the spring force balances the gravitational force.

Question 2

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?

Accepted Answer

The kinetic energy of an object attached to a spring is minimum (in fact, zero) at the points of maximum compression or extension, which are points A and B in this scenario. At these points, all the energy is potential, not kinetic.

Question 3

Two speakers are placed side by side and driven by the same frequency of 0.50 kHz. If the distance from a person to one speaker is 5.0 m and the person detects little or no sound, which of
The following is a possible the distance from the person to the other speaker? The sound speed in
The room is 340 m/s.

Accepted Answer

The answer of Two speakers are placed side by side...

Question 4

If we double the frequency of a system undergoing simple harmonic motion, which of the following statements about that system are true? (There could be more than one correct choice.)

Accepted Answer

The period of a system undergoing simple harmonic motion is inversely proportional to the frequency, so if the frequency is doubled, the period is halved (A). The angular frequency (ω) is directly proportional to the frequency (ω = 2πf), so if the frequency is doubled, the angular frequency is also doubled (D). The amplitude of the motion is independent of the frequency and is not affected by changes in frequency, so (B) is incorrect. (C) and (E) are incorrect based on the inverse relationship between period and frequency and the direct relationship between angular frequency and frequency, respectively.

Question 5

In simple harmonic motion, when is the speed the greatest? (There could be more than one correct choice.)

Accepted Answer

The speed is greatest when the potential energy is zero, which occurs at the equilibrium position where kinetic energy is maximum. At this point, the magnitude of acceleration is minimum.

Question 6

Grandfather clocks are designed so they can be adjusted by moving the weight at the bottom of the pendulum up or down. Suppose you have a grandfather clock at home that runs slow. Which
Of the following adjustments of the weight would make it more accurate? (There could be more
Than one correct choice.)

Accepted Answer

Raising the weight on the pendulum shortens the effective length of the pendulum, which increases the frequency of oscillation, making the clock run faster and more accurately if it was running slow.

Question 7

The half-angle of the conical shock wave produced by a supersonic aircraft is 60°. What is the ratio of the speed of the aircraft to the speed of sound?

Accepted Answer

The answer of The half-angle of the conical shock wave...

Question 8

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 maximum?

Accepted Answer

The elastic potential energy in a spring system is maximum when the spring is either most compressed or most stretched, which corresponds to the positions A or B if these are the extreme points of the motion.

Question 9

A mass on a spring undergoes SHM. When the mass passes through the equilibrium position, which of the following statements about it are true? (There could be more than one correct choice.)

Accepted Answer

At the equilibrium position, the mass has maximum kinetic energy because it is at its maximum speed (A), its elastic potential energy is zero because the spring is neither compressed nor stretched (C), and its acceleration is zero because it is at the point where the force on it changes direction (D).

Question 10

A pendulum of length L is suspended from the ceiling of an elevator. When the elevator is at rest the period of the pendulum is T. How does the period of the pendulum change when the elevator
Moves upward with constant velocity?

Accepted Answer

The period of a pendulum, $T = 2\pi\sqrt{\frac{L}{g}}$, depends only on the length of the pendulum and the acceleration due to gravity, g. When the elevator moves upward with constant velocity, there is no change in the acceleration due to gravity experienced by the pendulum, hence the period remains the same.

Question 11

In simple harmonic motion, when is the magnitude of the acceleration the greatest? (There could be more than one correct choice.)

Accepted Answer

The magnitude of acceleration in simple harmonic motion is greatest when the displacement from the equilibrium position is maximum, which corresponds to maximum potential energy and minimum kinetic energy.

Question 12

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 maximum?

Accepted Answer

The kinetic energy of an object attached to a spring is maximum at the equilibrium position, which is midway between the two extreme points (A and B) where the velocity of the object is greatest.

Question 13

A pendulum of length L is suspended from the ceiling of an elevator. When the elevator is at rest the period of the pendulum is T. How does the period of the pendulum change when the elevator
Moves downward with constant acceleration?

Accepted Answer

When the elevator moves downward with constant acceleration, the effective acceleration due to gravity (g') experienced by the pendulum is reduced. Since the period of a pendulum $T = 2\pi\sqrt{\frac{L}{g'}}$, a decrease in g' leads to an increase in the period T.

Question 14

A mass on a spring undergoes SHM. When the mass is at its maximum distance from the equilibrium position, which of the following statements about it are true? (There could be more
Than one correct choice.)

Accepted Answer

At the maximum distance from the equilibrium position, the mass is momentarily at rest, meaning its speed is zero. This is a characteristic of simple harmonic motion (SHM) where the velocity is zero at the maximum displacement due to all the energy being stored as potential energy at this point.

Question 15

An object attached to an ideal spring executes simple harmonic motion. If you want to double its total energy, you could

Accepted Answer

The answer of An object attached to an ideal spring...

Question 16

The total mechanical energy of a simple harmonic oscillating system is

Accepted Answer

The total mechanical energy in a simple harmonic oscillator is conserved and remains a non-zero constant, comprising both kinetic and potential energy, regardless of the position in its cycle.

Question 17

Two stereo speakers mounted 4.52 m apart on a wall emit identical sound waves. You are standing at the opposite wall of the room at a point directly between the two speakers. You walk 2.11 m
Parallel to the wall, to a location where you first notice that the sound intensity is essentially zero.
If the wall along which you are walking is 10.7 m from the wall with the speakers, what is the
Wavelength of the sound waves? The walls are cushioned to absorb sound reflections.

Accepted Answer

The path difference between the sound waves from the two speakers at the point of destructive interference is half a wavelength. Using the geometry of the situation and the Pythagorean theorem, the path difference can be calculated, leading to the wavelength of 1.71 m.

Question 18

Identical balls oscillate with the same period T on Earth. Ball A is attached to an ideal spring and ball B swings back and forth to form a simple pendulum. These systems are now taken to the
Moon, where g = 1.6 m/s², and set into oscillation. Which of the following statements about these
Systems are true? (There could be more than one correct choice.)

Accepted Answer

The answer of Identical balls oscillate with the same period...

Question 19

Grandfather clocks are designed so they can be adjusted by moving the weight at the bottom of the pendulum up or down. Suppose you have a grandfather clock at home that runs fast. Which of
The following adjustments of the weight would make it more accurate? (There could be more than
One correct choice.)

Accepted Answer

Lowering the weight increases the pendulum's length, which increases the period and slows down the clock, making it more accurate if it was running fast.

Question 20

A pendulum of length L is suspended from the ceiling of an elevator. When the elevator is at rest the period of the pendulum is T. How does the period of the pendulum change when the elevator
Moves upward with constant acceleration?

Accepted Answer

When the elevator moves upward with constant acceleration, the effective gravitational acceleration increases, which decreases the period of the pendulum.

Quiz 2: Describing Motion: Kinematics in One Dimension