P6 - Waves

Define amplitude.

The maximum displacement of a point from its rest position.

Define frequency.

The number of waves passing a point per second

Define wavelength

The distance between two corresponding parts of a wave

What direction do the longitudinal waves vibrate

Parallel to the direction of wave travel

What direction do the transverse waves vibrate

Right angles/perpendicular to the direction of wave travel.

Define angle of incidence

The angle between the incident ray and the normal.

Define angle of reflection.

The angle between the reflected ray and the normal

Define wave speed.

The speed which the waves travel through the medium.

Define medium

Material in which a wave travels.

Define time period

The time for one complete oscillation

Wave speed units

m/s.

Wave speed =

frequency x wavelength

Frequency =

1/time period

time period =.

1/frequency.

Frequency units

Hz (Hertz.)

Wavelength unit

m.

wave speed symbol =

V.

Frequency symbol =

F.

Wavelength symbol

λ(lambda).

λ =

wavelength

Where do sound waves enter the ear

outer ear structures

After hitting the ear flap, where do sound waves travel down

Vibrate down the ear canal

Define ultrasound

A frequency above the threshold of human hearing.

What frequency is ultrasound above

2x10^4

What do sound waves consist of?

Pressure waves.

What vibrates after the eardrum?

Small bones in the middle ear

Where do the pressure waves move to in the ear?

The cochlear.

How is an electrical impulse generated from the cochlear

Hair and fibres stimulate a response.

What do s-waves travel through

Only solids

What do p-waves travel through

Solids and liquids

What causes the s-wave "shadow zone"?

Being stopped entirely by the liquid core

Which of the electromagnetic spectrum has the longest wavelength

Radio waves

Which of the electromagnetic spectrum has the shortest wavelength?

gamma rays.

Which of the electromagnetic spectrum has are ionising radiation

Ultraviolet.

Xrays

Gamma Rays.

What visible light is refracted the least?

Red.

What visible light is refracted the most

Violet

What is the speed of sound?

340 m/s

What is the speed of light?

3x10^8 m/s.

Maximum displacement=

Amplitude.

Distance of one entire oscillation

Wavelength

Time it takes for one complete oscillation

Time period

Number of complete oscillations per second=

Frequency.

What do waves transfer from one location to another?

Energy

Is sound long or trans?

Longitudinal

The distance from the lens to the principal focus is called the...

focal length

Which type of electromagnetic waves are the most penetrating?

gamma

What kind of object returns to its original shape when the force stops acting on it?

elastic

What is the upper limit of frequencies able to be heard by humans?

20 000 hz

A wave where the oscillations are perpendicular to the direction of energy transfer is a:

transverse wave

A wave where the oscillations are parallel to the direction of energy transfer is a:

longitudinal wave

What type of image will specular reflection produce?

A clear image

Light travels more ________ in a more dense material.

slowly

Light travelling from a less dense material, into a more dense material, will bend ________ the normal.

towards

Are longitudinal waves p or s?

primary (p)

Are transverse waves p or s?

secondary (s)

What type of wave are sound waves?

longitudinal

What type of wave are all electromagnetic waves?

transverse

What unit is used for frequency?

Hz

When will light reflect?

when the object is opaque and not absorbed by the material

When will light transmit?

when waves pass through a transparent material

When will waves be absorbed?

If the frequency of light matches the energy levels of the electrons

What is white light?

A combination of all wavelengths of visible light

What determines how transparent / translucent an object is?

The proportion of transmitted light

What is an opaque object?

An object that does not transmit any light

Objects that are hotter than their surroundings emit ________ radiation than they absorb.

more

Define intensity (for radiation)

power of the radiation per unit area

What happens to the wavelength emitted as an object gets hotter?

It decreases

What are oscilloscopes used for?

To display the frequency of an alternating current

Can transverse waves travel through a vacuum?

Yes

What type of waves are electromagnetic waves?

transverse waves

What property of the light wave changes when it is refracted?

wave speed (and so wavelength)

What happens to the speed of a wave if it passes through a more dense material?

slows

What happens to the direction of a slower moving wave in a denser material?

bends towards the normal

Define visible light

Spectrum of wavelengths that our eyes can detect

What type of reflection occurs as visible light travels through optical fibres?

Specular

Define fluorescence

UV light being absorbed and re-emitted as visible light

True or false: s-waves are longitudinal and p-waves are transverse

False