1. Q15.1
If you double the wavelength l of a wave on a string, what happens to the wave speed v and the wave frequency f?
1. v is doubled and f is doubled
2. v is doubled and f is unchanged
3. v is unchanged and f is halved
4. v is unchanged and f is doubled
5. v is halved and f is unchanged

2. A15.1
If you double the wavelength l of a wave on a string, what happens to the wave speed v and the wave frequency f?
1. v is doubled and f is doubled
2. v is doubled and f is unchanged
3. v is unchanged and f is halved
4. v is unchanged and f is doubled
5. v is halved and f is unchanged

3. Q15.2
Which of the following wave functions describe a wave that moves in the –x–direction?
1. y(x,t) = A sin (–kx – wt)
2. y(x,t) = A sin (kx + wt)
3. y(x,t) = A cos (kx + wt)
4. both 2. and 3.
5. all of 1., 2., and 3.

4. A15.2
Which of the following wave functions describe a wave that moves in the –x–direction?
1. y(x,t) = A sin (–kx – wt)
2. y(x,t) = A sin (kx + wt)
3. y(x,t) = A cos (kx + wt)
4. both 2. and 3.
5. all of 1., 2., and 3.

5. Q15.3
A wave on a string is moving to the right. This graph of y(x, t) versus coordinate x for a specific time t shows the shape of the wave at that time.
What are the velocity and acceleration of a particle at point P on the string?
1. velocity is upward and acceleration is zero
2. velocity is downward and acceleration is zero
3. velocity is zero and acceleration is upward
4. velocity is zero and acceleration is downward
5. none of the above

6. A15.3
A wave on a string is moving to the right. This graph of y(x, t) versus coordinate x for a specific time t shows the shape of the wave at that time.
What are the velocity and acceleration of a particle at point P on the string?
1. velocity is upward and acceleration is zero
2. velocity is downward and acceleration is zero
3. velocity is zero and acceleration is upward
4. velocity is zero and acceleration is downward
5. none of the above

7. Q15.4
A wave on a string is moving to the right. This graph of y(x, t) versus coordinate x for a specific time t shows the shape of the wave at that time.
What are the velocity and acceleration of a particle at point Q on the string?
1. velocity is upward and acceleration is zero
2. velocity is downward and acceleration is zero
3. velocity is zero and acceleration is upward
4. velocity is zero and acceleration is downward
5. none of the above

8. A15.4
A wave on a string is moving to the right. This graph of y(x, t) versus coordinate x for a specific time t shows the shape of the wave at that time.
What are the velocity and acceleration of a particle at point Q on the string?
1. velocity is upward and acceleration is zero
2. velocity is downward and acceleration is zero
3. velocity is zero and acceleration is upward
4. velocity is zero and acceleration is downward
5. none of the above

9. Q15.5
The four strings of a musical instrument are all made of the same material and are under the same tension, but have different thicknesses. Waves travel
1. fastest on the thickest string
2. fastest on the thinnest string
3. at the same speed on all strings
4. not enough information given to decide

10. A15.5
The four strings of a musical instrument are all made of the same material and are under the same tension, but have different thicknesses. Waves travel
1. fastest on the thickest string
2. fastest on the thinnest string
3. at the same speed on all strings
4. not enough information given to decide

11. Q15.6
While a guitar string is vibrating, you gently touch the midpoint of the string to ensure that the string does not vibrate at that point.
The lowest-frequency standing wave that could be present on the string
1. vibrates at the fundamental frequency
2. vibrates at twice the fundamental frequency
3. vibrates at three times the fundamental frequency
4. vibrates at four times the fundamental frequency
5. not enough information given to decide

12. A15.6
While a guitar string is vibrating, you gently touch the midpoint of the string to ensure that the string does not vibrate at that point.
The lowest-frequency standing wave that could be present on the string
1. vibrates at the fundamental frequency
2. vibrates at twice the fundamental frequency
3. vibrates at three times the fundamental frequency
4. vibrates at four times the fundamental frequency
5. not enough information given to decide