#175 (Q) Unit 7 Test Review for Re-take

Andrew notices that when he presses the string of his guitar down at the red line, the pitch is higher than when he presses down at the blue line. What can explain this phenomenon?

• Pressing down on the string at the red line causes interference which leads to a change in pitch.

• Pressing down on the string at the red line shortens the string and makes it vibrate slower, which increases the pitch.

• Pressing down on the string at the red line shortens the string and makes it vibrate faster, which increases the pitch.

According to the graph above, what can she determine about the effect of water temperature on the speed of sound?

• A. Water temperature does not affect the speed at which sound waves will travel through it.

• B. As water temperature increases, sound waves travel slower.

• C. As water temperature increases, sound waves travel faster.

• D. As water temperature decreases, sound waves travel faster.

When several trumpets play the same note at the same time, they make a louder sound. This is called _____.

• resonance

• destructive interference

• reflection

• diffraction

The red and blue lines represent two waves interacting with one another. The black line represents the overall sum of the red and blue waves. Choose the best description of what is happening in each illustration.

• Illustration (a) = constructive interference; Illustration (b) = resonance

• Illustration (a) = constructive interference; Illustration (b) = destructive interference

• Illustration (a) = destructive interference; Illustration (b) = constructive interference

• Illustration (a) = resonance; Illustration (b) = constructive interference

Match each number with its corresponding part on the wave pictured above.

• wavelength

• 2

• rarefaction

• 3

• compression

• 1

As the amplitude of a wave increases, the amount of energy it carries (a)   .

• increases

• decreases

Choose the best answer to complete the statement. As the frequency of a wave increases, its wavelength (a)   . Options: increases, decreases.

• increases

• decreases

A wave with a lower frequency has (a)   energy than a wave with a higher frequency.

• more

• less

In a wave​ ​ (a)   , energy moves in a straight path through the medium. An example of this would be ​ (b)   waves.

• longitudinal
• transverse
• sound
• light

Match each number to the correct part of the wave.

• 1

• amplitude

• 4

• crest

• 3

• trough

• 2

• wavelength