HARMONIC WAVES IN WHALE SOUNDS

WHALES PRODUCE SOUNDS FOR:

Navigation Communication Hunting

THE SPEED OF SOUND WAVES

In air is ~340m/s In water is

~1500m/s

HEARING RANGE

Humans: 20 ~ 20,000 Hz

Whales: 500 ~ 31,000 Hz

QUESTION PART 1

Suppose that you and your friends were on a boat in the ocean. You were having a conversation when a whale swam by. The wavelength of the sound produced by you was approximately 17cm. Can the whale sense the sound?

Hint 1: You are given the wavelength of the sound,

can you find the frequency?

Hint 1: You are given the wavelength of the sound,

can you find the frequency?

Hint 2: Use the equation: v=λf

Solution: v=λf f= = f=2000Hz Note that frequency does not change when

the wave moves from one medium to another Whales can hear sound frequencies between 500

~ 31,000 Hz

∴ The whale can sense the sound

Rearrange the formula and solve for f

Use the speed of sound in AIR because you and your friends

are not underwater

Watch out for units

QUESTION PART 2

Whales use whistles for close-range communication. The whistles produced by the whale have a wave number of approximately 8π rad/m. Can you, standing on the boat, hear the whistles?

Hint 1: You are given the wave number of the sound,

can you find the wavelength?

Hint 1: You are given the wave number of the sound,

can you find the wavelength?

Hint 2: Use the equation: k=

Hint 1: You are given the wave number of the sound,

can you find the wavelength?

Hint 2: Use the equation: k= Rearrange the equation and solve for λ λ===0.25m

Hint 1: You are given the wave number of the sound,

can you find the wavelength?

Hint 2: Use the equation: k= Rearrange the equation and solve for λ λ===0.25m Find the frequency of the sound produced by

the whale

Solution: k= λ===0.25m v=λf f== f=6000Hz Note that frequency does not change when the

wave moves from one medium to another Humans can hear sound frequencies between 20 ~

20,000 Hz

∴ You will be able to hear the whale whistle

Use the speed of sound in WATER because the whale is in

water when it whistled

Thank you for Watching

WORK CITED

“Killer Whales Communication & Echolocation.” SeaWorld Parks & Entertainment. SeaWorld Parks & Entertainment. n.d. Web. 8 Feb. 2015. < http://seaworld.org/animal-info/animal-infobooks/killer-whale/communication-and-echolocation/>.

“Killer Whales Senses.” SeaWorld Parks & Entertainment. SeaWorld Parks & Entertainment. n.d. Web. 8 Feb. 2015. < http://seaworld.org/animal-info/animal-infobooks/killer-whale/communication-and-echolocation/>.