Lecture 3

Question 1

Definition of wavelength:

Answer 1

The length of space that one wave occupies.

Question 2

For the graph that displays wavelength, what is found on the X and Y axis?

Answer 2

X axis - Distance/particle motion.

Y axis - Pressure or amplitude.

Question 3

Wavelength equation:

Answer 3

Wavelength = Speed/Frequency

Question 4

Shorter wavelengths (higher frequencies) produce:

Answer 4

Better resolution and poorer penetration.

Question 5

Wavelength is affected by:

Answer 5

The source of sound (transducer frequency) and the medium.

Question 6

T/F: The speed that sound travels through a medium is dependent on the frequency of the wave.

Answer 6

False

Question 7

Which variable has the greatest effect on the speed that a wave travels through a medium?

Answer 7

Bulk modulus.

Question 8

As stiffness increases, the speed of sound:

Answer 8

Increases.

Question 9

As density decreases, the speed of sound:

Answer 9

Increases.

Question 10

Impedance equation:

Answer 10

Z = PC
Impedance = Density x Speed

Question 11

Impedance increases if:

Answer 11

Propagation speed or density increases.

Question 12

Two properties of medium that affects speed of sound:

Answer 12

1. Hardness of medium (Stiffness, Bulk Modulus).

2. Density of medium.

Question 13

When density increases, the speed of sound:

Answer 13

Decreases.