Unit 9 Practice Questions

A mechanical wave moves through a medium, which can be

• A liquid
• A solid
• A gas
• All of the others

Which type of mechanical wave needs a source of energy to produce it?

• A transverse wave
• A longitudinal wave
• A surface wave
• All of the others

Which wave causes particles in a medium to move only in the same direction as the wave’s energy?

• A transverse wave
• A surface wave
• A longitudinal wave
• None of the others

A period is the amount of time it takes for

• A disturbance to start a wave
• Two complete wavelengths to pass by
• One complete wavelength to pass by
• A wave to travel the length of a string

To determine the velocity of a wave, you would use which of the following formulas?

• velocity = frequency × amplitude
• velocity = wavelength × frequency
• velocity = wavelength × amplitude
• velocity = wavelength × period

A wave has a wavelength of .010 m and a frequency of 5.0 hertz. What is its velocity?

• 0.050 m/s
• 50 Hz/s
• 0.002 m/s
• 0.0005 m/s

To find amplitude, you measure

• from a trough to the rest position.

• From a crest to the rest position

• From to top the the crest to the bottom of the trough

What is amplitude related to? (Hint: think about the volume of sound)

• the amount of energy carried by the wave

• the maximum displacement from the rest position

• neither energy nor displacement

• both energy and displacement

How does reflection differ from refraction and diffraction?

• Reflection is the only process in which the wave does not continue moving forward.
• Reflection is the only process that involves a change in the wave.
• Reflection affects all types of mechanical waves, but refraction and diffraction do not.
• Reflection is the only process that changes the direction of a wave.

In refraction, when a wave travels from one medium to another, it

• changes speeds.
• doesn’t change
• always moves in the same direction.
• travels in the opposite direction.