Question 1

Why does the intensity of waves from a small source decrease with the square of the distance from the source?
A) The frequency of the waves decreases as they get farther from the source.
B) The waves run out of energy as they travel.
C) The medium through which the waves travel absorbs the energy of the waves.
D) The waves slow down as they travel away from the source.
E) The waves spread out as they travel.

Accepted Answer

The intensity of waves decreases with the square of the distance from the source because the energy of the waves is spread out over a larger area as they travel. This phenomenon is described by the inverse square law, which applies to point sources emitting waves in three-dimensional space. As the distance from the source increases, the surface area over which the energy is distributed increases as the square of the distance, leading to a decrease in intensity.

Question 2

Which one of the curves shown in the figure best represents the variation of wave speed v as a function of tension for transverse waves on a stretched string?

A)  A 
B)  B 
C) C
D)  D 
E) E

Accepted Answer

B

Question 3

A string of length  L  is under tension, and the speed of a wave in the string is  What will be the speed of a wave in the string if the length is increased to  2 L  but with no change in the mass or tension?
A) 
B) 
C) 
D) 
E)

Accepted Answer

D

Question 4

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? 
A)  2T 
B)  T 
C)  T/2 
D) 
E)

Accepted Answer

The answer of Two simple pendulums, A and B, are...

Question 5

If a guitar string has a fundamental frequency of  500 Hz, which one of the following frequencies can set the string into resonant vibration?
A)  1750 Hz
B)  1500 Hz
C)  250 Hz
D)  750 Hz

Accepted Answer

Resonant vibration occurs at frequencies that are integer multiples of the fundamental frequency. For a fundamental frequency of 500 Hz, the resonant frequencies would be 1000 Hz (2nd harmonic), 1500 Hz (3rd harmonic), 2000 Hz (4th harmonic), etc. Therefore, 1500 Hz can set the string into resonant vibration.

Question 6

What is the wavelength of the wave shown in the figure?

A) 8 m
B) 4 m
C) 1 m
D) 2 m
E) It cannot be determined from the given information

Accepted Answer

The answer of What is the wavelength of the wave...

Question 7

The intensity of the waves from a point source at a distance d from the source is I . What is the intensity at a distance  2d  from the source?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of The intensity of the waves from a...

Question 8

When a certain string is under tension  T , the speed of a wave in the string is  m What will be the speed of a wave in the string if the tension is increased to  2T   without changing the mass or length of the string?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of When a certain string is under tension...

Question 9

What is the frequency of the wave shown in the figure?

A) 4 Hz
B) 0.5 Hz
C) 2 Hz
D) 1 Hz
E) It cannot be determined from the given information

Accepted Answer

The answer of What is the frequency of the wave...

Question 10

The intensity of the waves from a point source at a distance  d  from the source is  I . At what distance from the sources is the intensity equal to  2I?
A) 
B) 
C) 
D)

Accepted Answer

The answer of The intensity of the waves from a...

Question 11

A simple harmonic oscillator oscillates with frequency f when its amplitude is A. If the amplitude is now doubled to 2A, what is the new frequency? 
A) 
B) 
C)  
D) 
E)

Accepted Answer

The answer of A simple harmonic oscillator oscillates with frequency...

Question 12

An object that hangs from the ceiling of a stationary elevator by an ideal spring oscillates with a period T. If the elevator accelerates upward with acceleration 2g, what will be the period of Oscillation of the object? 
A)  T/4 
B)  T 
C)  2T 
D)  4T 
E)  T/2

Accepted Answer

The period of oscillation of an object on a spring is given by $T = 2\pi\sqrt{\frac{m}{k}}$, where $m$ is the mass of the object and $k$ is the spring constant. This formula shows that the period $T$ is independent of the acceleration of the system, including gravity. Therefore, even if the elevator accelerates upward with acceleration $2g$, the period of oscillation $T$ remains unchanged.

Question 13

The figure shows a graph of the velocity v as a function of time t for a system undergoing simple harmonic motion. Which one of the following graphs represents the acceleration of this system as a Function of time?

A) graph a
B) graph b
C) graph c
D) graph d

Accepted Answer

The answer of The figure shows a graph of the...

Question 14

When a guitar is tuned to adjust it pitch, what is it that is changed?
A) The wavelength of the fundamental.
B) The amplitude of the fundamental.
C) The frequency of the fundamental.

Accepted Answer

When a guitar is tuned to adjust its pitch, the frequency of the fundamental note is what is being changed. Adjusting the tension of the strings changes the frequency at which they vibrate, thereby altering the pitch.

Question 15

A string of mass  m  is under tension, and the speed of a wave in the string is   What will be the speed of a wave in the string if the mass of the string is increased to  2 m but with no change in the length or tension?
A) 
B) 
C) 
D) 
E)

Accepted Answer

The answer of A string of mass  m ...

Question 16

Four waves are described by the following equations, where distances are measured in meters and times in seconds.
 
Which of these waves have the same period?
A) I and II, and also III and IV
B) I and III, and also II and IV
C) I and IV, and also II and III
D) All of them have the same period.
E) They all have different periods.

Accepted Answer

The answer of Four waves are described by the following...

Question 17

The figure shows a graph of the position x as a function of time t for a system undergoing simple harmonic motion. Which one of the following graphs represents the acceleration of this system as a Function of time?

A) graph a
B) graph b
C) graph c
D) graph d

Accepted Answer

The answer of The figure shows a graph of the...

Question 18

Four waves are described by the following equations, where distances are measured in meters and times in seconds.

Which of these waves have the same speed?
A) II and IV
B) I and II
C) I and III
D) III and IV
E) II and III

Accepted Answer

The answer of Four waves are described by the following...

Question 19

The figure shows a graph of the position x as a function of time t for a system undergoing simple harmonic motion. Which one of the following graphs represents the velocity of this system as a
Function of time?

A) graph a
B) graph b
C) graph c
D) graph d

Accepted Answer

The answer of The figure shows a graph of the...

Question 20

A ball swinging at the end of a massless string, as shown in the figure, undergoes simple harmonic motion. At what point (or points) is the magnitude of the instantaneous acceleration of the ball the Greatest?

A)  A and D 
B) B
C)  A and C 
D)  A and B 
E)  C

Accepted Answer

The answer of A ball swinging at the end of...

Quiz 11: Oscillations and Waves

Why does the intensity of waves from a small source decrease with the square of the distance from the source?

Which one of the curves shown in the figure best represents the variation of wave speed v as a function of tension for transverse waves on a stretched string?

A string of length L is under tension, and the speed of a wave in the string is What will be the speed of a wave in the string if the length is increased to 2 L but with no change in the mass or tension?

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?

If a guitar string has a fundamental frequency of 500 Hz, which one of the following frequencies can set the string into resonant vibration?

What is the wavelength of the wave shown in the figure?

The intensity of the waves from a point source at a distance d from the source is I . What is the intensity at a distance 2d from the source?

When a certain string is under tension T , the speed of a wave in the string is m What will be the speed of a wave in the string if the tension is increased to 2T without changing the mass or length of the string?

What is the frequency of the wave shown in the figure?

The intensity of the waves from a point source at a distance d from the source is I . At what distance from the sources is the intensity equal to 2I?

A simple harmonic oscillator oscillates with frequency f when its amplitude is A. If the amplitude is now doubled to 2A, what is the new frequency?

An object that hangs from the ceiling of a stationary elevator by an ideal spring oscillates with a period T. If the elevator accelerates upward with acceleration 2g, what will be the period of Oscillation of the object?

The figure shows a graph of the velocity v as a function of time t for a system undergoing simple harmonic motion. Which one of the following graphs represents the acceleration of this system as a Function of time?

When a guitar is tuned to adjust it pitch, what is it that is changed?

A string of mass m is under tension, and the speed of a wave in the string is What will be the speed of a wave in the string if the mass of the string is increased to 2 m but with no change in the length or tension?

Four waves are described by the following equations, where distances are measured in meters and times in seconds. Which of these waves have the same period?

The figure shows a graph of the position x as a function of time t for a system undergoing simple harmonic motion. Which one of the following graphs represents the acceleration of this system as a Function of time?

Four waves are described by the following equations, where distances are measured in meters and times in seconds. Which of these waves have the same speed?

The figure shows a graph of the position x as a function of time t for a system undergoing simple harmonic motion. Which one of the following graphs represents the velocity of this system as a Function of time?

A ball swinging at the end of a massless string, as shown in the figure, undergoes simple harmonic motion. At what point (or points) is the magnitude of the instantaneous acceleration of the ball the Greatest?