PY 131 Module 16 - Sound

Definition of sound

A series of longitudinal waves traveling through some medium

Direction of travel of longitudinal waves

Parallel to the direction of motion

Define rarefaction

Sections of a sound wave where there is less compression

How to low and high frequencies relate to pitch

Low frequency equals low pitch and vice versa

What is wave speed dependent on

Only on the wave medium

What is the speed of sound in miles per hour and meters per second

767 miles/h and 343 m/second

Angle of incidence of a sound wave

Equal to the angle of reflection

Sound Speed and warm versus cool mediums

Sound troubles faster and more mediums than cooler mediums

How does the nature of sound help submarines avoid detection

Kinds of Cherokee layers of temperature gradients at different depths and fraction of sound leaves gaps and blind spots in the water

What is the cause of refraction

Differences in wave speeds

Define refraction

Depending of sound

Is ultrasound higher or lower than we can hear

Higher

What happens when one part of a wave moves faster than another

Refraction: the overall direction of the wave bends

How can sound be Amplified

By placing the vibrating object in contact with the surface also able to vibrate at that frequency

Give an example of a poor resonator

Putty

Resonance between a pair of tuning Forks occurs best for Forks that have matched…

Frequencies

To increase the amplitude of a child on a swing it is important that your pushes are…

Properly timed

Superposition principle

When more than one vibration shares a time and space the displacements of the Waves add at every point

Define Beats

Periodic variations in the loudness of two mismatched frequencies

How do you find the frequency of beats per cycle

The difference between frequencies in Hertz

How can you make a tuning fork sound louder

Hold it against a table top with its base

The picture of your voice is raised after inhaling helium gas. This is because sound travels…

Faster than helium air which means it has a higher frequency

Why is a guitar louder than a ukulele

The guitar has a larger sounding board

How is resonance like forced vibration

It's forced vibration with the least amount of energy input

To get an object vibrating with the least amount of energy the forced vibration should be..

At it's frequency

What happens to the pitch of a wine glass as you fill it with wine

The pitch decreases

What is the wavelength of a 340 HZ sound traveling at 340 m/s in air

1 m

A healthy range of human hearing typically covers what frequencies

20 Hertz to 20,000 Hertz

A tuning fork sounds louder when it's handle is pressed to a table but does it also sound longer

It actually sounds for a shorter duration

Which do we hear better, infrasonic or ultrasonic?

Neither they're defined by the ranges that we can't hear

At 1,000 Hertz a wave vibrates how fast?

1000 cycles per second

What does the natural frequency of an object depend on

It's size shape and elasticity

Longitudinal waves of different lengths are traveling through a long metal rod those that travel at the greatest speed are

None of these choices

Is it possible for two sounds to cancel each other

Yes

In what medium does sound travel fastest?

Steel

An opera singer shattering a crystal glass with her voice is an example of?

Resonance

In what phase of water does sound travel the fastest?

Ice

When the speed of sound near the ground is greater than higher in the air sound tends to be bent which way

Upward

An oceanic depth sounding vessel surveys the ocean bottom with ultrasonic waves that travel 1,530 m/s in seawater. How deep is the water directly below the vessel if the time delay of the echo to the ocean floor and back is 8.5 seconds?

6502.5 m

Use 340 m per second for the speed of sound.

You watch a distant woman driving nails into her front porch at a regular rate of one stroke per second. You hear the sound of the blows exactly synchronized with the clothes you see. And then you hear five more blows after you see her stop hammering. How far away is she?

1700 m