Waves and Sound

A sound wave has a frequency of 425 Hz. What is the period of this wave?

0.00235 seconds

A marching band is practicing. The band director sees the drum major hit a drum. How far away is the director if he hears the drumbeat in 0.40 seconds? The speed of sound is 330 m/s.

132 m

What is the amplitude of this wave?

2.1 cm

Which correctly identifies the parts of a transverse wave?

A: crest B: amplitude C: trough D: wavelength

Why does a shirt appear white outside on a sunny day?

All the light is reflected, so the shirt appears white.

What is the name of the perceived change in a sound wave's frequency due to motion between the observer and the sound source?

Doppler effect

What best describes the difference between the second sound wave and the first?

The air molecules in the compressions of the second wave are more dense.

A band director instructs students to play a pitch louder. How will the sound wave change when the band plays the same pitch louder?

The amplitude of the sound wave will increase.

What best describes the pitch that Juan hears?▫️

The pitch drops to a lower pitch once the ambulance passes by Juan.

What best describes the speed of light waves in solids, liquids, and gases?

The speed is the fastest in gases.

A sound wave travels through water. What best describes the direction of the water particles?

The water particles move in the same direction as the vibrating source of the sound wave.

How are electromagnetic waves different than all other waves?

They can travel through space.

What conclusion does the student most likely make based on this data?

Tightly packed particles in solids slow down the light waves; however, sound waves make particles bounce into each other, so they travel faster in solids.

If an electromagnetic wave's frequency doubles in a vacuum, what are the other effects on the wave?

Wavelength divides in half and speed stays the same.

\/\/\/\/ |-------| . 1 sec Which shows the perceived sound wave heard by a stationary observer when the source moves toward the observer.

\/\/\/\/\/\/\/ |--------------| . . . .1 sec

What part of the wave determines how much energy it has?

amplitude period velocity

Identify point B.

crest

A tuning fork is vibrating the air around it. What best describes the waves produced by the tuning fork?

mechanical, because the air molecules are moving perpendicular to the tuning fork mechanical, because the vibrating tuning fork makes air molecules around it vibrate

An ambulance emits a frequency of 450 Hz from its siren. What frequency is heard by a man as the ambulance moves toward him?

more than 450 Hz

A longitudinal wave moves energy that is [________________________] to the direction of the wave's movement.

parallel

Point C identifies the [______________] of the wave.

trough

Which color of light has the greatest frequency?▫️

violet

In an experiment, a ringing bell is placed in a vacuum jar that does not have any air in it. What best describes why the bell is seen vibrating but not heard?

Light does not need a medium to travel through, but since sound waves must have a medium to vibrate, sound is not created where no air is present.

What is the difference in wavelength between the wave produced in ice and the wave produced in water?

3.1 m

An FM radio station broadcasts at 9.23 × 10⁷ Hz. Given that the radio waves travel at 3.00 × 10⁸ m/s, what is the wavelength of these waves?

3.25 m

If argon could exist as a solid, what would best represent the speed through solid argon?

3200 m/s

A flute plays a note with a frequency of 266 Hz. What is the speed of sound if the wavelength is 1.3 m?

346 m/s

What best describes a possible transfer of energy?

A mechanical wave transfers energy through matter.

Which is the best example of the wave phenomenon called transmission?

A street is seen through a window. Sound is heard around an open doorway. An image of a tree is seen is on the surface of a smooth lake.

Ten students stand in a circle and are told to make a transverse wave. What best describes the motion of the students?

One at a time, each student lifts his or her hands up and then down.

Which best explains why sound travels fastest through a solid?

Sound is a mechanical wave, so closer molecules in the medium cause energy to transfer faster.

What best explains the speed of sound in different states of matter?

Sound travels fastest in ice because energy is easier to transfer when the molecules are close together.

Which best describes the energy of a sound wave as it travels through a medium?

It decreases.

A guitar string is plucked. What best describes the formation and transmission of the sound wave?

The string vibrates the surrounding air, which produces a longitudinal wave.

How will sunlight most likely affect a black shirt on a hot summer day?

The temperature of the shirt will increase because all wavelengths of light are absorbed by the shirt.

What is the cause of the beats?

The two waves produced have different speeds. The two waves produced have different wavelengths. The two waves produced have different frequencies.

How are electromagnetic waves different than all other waves?▫️

They can travel through space.

Which diagram shows the resulting wave when they cross at point X? →. . . .← __/\__/\__ . . . X

___/\___

What interaction causes the water to spread as they pass through the rock opening?

diffraction

What type of wave activity is shown in the image?

diffraction

a soundproof door is almost shut but still leaves a small opening, what wave phenomenon is responsible for someone being able to hear sound from the room while standing by the wall to the side of the opening?

diffraction

What wave phenomenon is responsible for the sunlight shown in this diagram?

diffraction, because light is bent around the clouds

What is transmitted by all waves?

energy

How many wavelengths are seen in this image of a sound wave?

four

What best describes the relationship between wavelength and frequency in an electromagnetic wave?

inversely proportional

What best describes the refraction of light rays?▫️

light bending when it passes through a lens

What best describes a SONAR wave?

longitudinal and electromagnetic longitudinal and mechanical

The [__________________] is the time it takes for a wave to complete one cycle.

period

As the source moves west, which person hears the highest pitch?

person A

A sound wave travels through air. In which regions are air molecules the least dense?

rarefactions

What two factors affect the speed of a sound wave as it travels through a medium?

the type of medium and the temperature of the medium

Which equations represent the relationship between wavelength and frequency for a sound wave? Check all that apply. v = λf λ = vf f = λv λ = v/f λ = f/v f = v/λ f = λ/v

v = hf h = v/f f = v/h (the "h" represents the lambda...just go with it)

Sound will travel slowest through which medium?

water at 55°C

Which sound wave has the lowest pitch?

|__| | | | | | | |||| | | | | | | . |

What is the direction of the Slinky wire at Point P as the waves travel through this point?

←•→

Which diagram shows the resulting interference?

🚫___/-\____-___-___-__/\_____/\ . . .\/. . . \/. . -. .-. . -. . .\-/

What factors affect the speed of a wave? Check all that apply. the amplitude of the wave the energy of the wave the temperature of the medium the type of wave the type of medium

🚫◻️✔️✔️◻️✔️ 🚫✔️✔️◻️◻️✔️

What are examples of devices that use electromagnetic waves? Check all that apply.

🚫✔️◻️✔️◻️✔️ 🚫◻️✔️◻️◻️✔️ FM radios, microwaves, TV remote controls, alarm clocks, X-rays

Which voice can produce a pitch that has a speed of 343 m/s and a wavelength of 0.68 m? Check all that apply. bass baritone tenor contralto soprano

🚫✔️✔️✔️✔️◻️ _◻️◻️◻️✔️✔️

What is the purpose of a rearview mirror in a car?

The mirror allows the light to be reflected so the objects behind the car can be seen.

Which diagram best shows the perceived sound wave heard by a woman after a police car has passed her? (circles as parenthesis)

( . . . ( . . . ( . . . ( • ))))

Which statements best describe X-rays? Check all that apply.

-X-rays are electromagnetic waves. -X-rays are transverse waves. -X-rays travel at the speed of light.

The straw appears to "bend" because of [_________________].

-refraction

Which diagram shows the appearance of the string after the pulses pass point P? . . . ._____ → P ____| . . .|____•____ . . ____ . . . . . . . . . . . .←\/

. . . . . . . .P. . . _____→ ____ . . ____•____| . . .|____ . ←\/

What wavelength is produced?

1.5 m