Understanding Sound Waves

What initiates the movement of molecules in a medium to produce sound?

• Gravity pulling on the objects

• Electrical impulses

• Force from a vibrating object

• Heat from the sun

What unit is used to measure the frequency of sound?

• Watts

• Newton

• Hertz

• Decibels

Which range of sound frequencies can typically be heard by humans?

• 20 to 20,000 Hertz

• 10 to 10,000 Hertz

• 5 to 25,000 Hertz

• 15 to 15,000 Hertz

What does the amplitude of a sound wave determine?

• Weight

• Color

• Length

• Loudness

Up to what sound level in decibels can a person with normal hearing tolerate?

• 100 decibels

• 110 decibels

• 120 decibels

• 130 decibels

Which sound wave has high frequency?

• sound wave 1

• sound wave 2

• sound wave 3

• sound wave 4

Answer explanation

The sound wave with high frequency is sound wave 4.

When a sound is louder what measurement gets bigger?

• Frequency 

• Amplitude 

• Wavelength 

• Crest

Answer explanation

When a sound is louder, the measurement that gets bigger is the Amplitude. Amplitude is the measure of the strength or intensity of a sound wave.

The measure of how high or low a sound is:

• the intensity

• the size of the wavelength

• how loud or soft a sound is

• the frequency

Answer explanation

The measure of how high or low a sound is determined by its frequency, not by the intensity, size of the wavelength, or how loud or soft it is.

The amplitude is represented by letter ​​ ​ (a)  

• A
• C
• D
• E
• F
• B