REVIEW: Waves Modules 9,10,11

wave

a disturbance in matter that carries energy from one place to another

medium

material through which a mechanical wave travels such as air, water, soil, glass

Which type of wave can travel through a vacuum?

electromagnetic waves

Which type of waves require matter (a medium) to travel though?

mechanical waves

Crest

The highest point of the wave above the rest position

Trough

The lowest point of the wave below the rest position

Transverse wave

A wave in which particles of medium move PERPENDICULAR to the direction in which the wave travels

Compression

An area of a longitudinal wave where the particles in a medium are spaced close together

Rarefaction

An area of a longitudinal wave where the particles in a medium are spread out

Longitudinal wave

A wave in which the movement of the medium particles is PARALLEL to or in the same direction as the direction the wave travels

What is frequency measured in?

wave cycles per second or hertz (Hz)

Wavelength

The distance between a point on one wave and the same point on the next cycle of the wave such as from crest to crest

How is wavelength measured for a transverse wave?

It is the distance measured between two crests or between two troughs

How is wavelength measured for a longitudinal wave?

It is the distance between one compression to the next compression

What does increasing the frequency of a wave do to its wavelength?

The wavelength decreases

How do you calculate speed of a wave?

Speed\= Wavelength x Frequency

Amplitude

The maximum displacement of the medium from its rest position; 1/2 the wave height

An increased amplitude of a sound wave results in

greater loudness and energy

Sound waves

compressions and rarefactions that travel through a medium; they are longitudinal waves

high frequency sound

high pitch sound that adults are gradually unable to hear with age

High frequency sounds have a \__________ pitch, and low frequency sounds have a \______ pitch

high; low

If the speed of a wave is 335 m/s and its frequency is 67 Hz, what is its wavelength?

5 m; speed divided by frequency\= wavelength

Which type of medium does sound travel fastest though?

usually the most dense, rigid solids

Does sound travel faster through solids, liquids, or gases?

Sound travels fastest in solids because the particles in a solid are closer together than in liquids or gas

electromagnetic waves

A form of energy that can move through the vacuum of space.

longest wavelength form of electromagnetic radiation

radio waves

order of visible light colors from lowest energy to highest energy

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Which type of electromagnetic radiation is used to kill cancer cells?

gamma rays

Reflection

The bouncing back of a wave when it hits a surface through which it cannot pass.

Refraction of light

The bending of light as it passes from one medium to another

Type of electromagnetic radiation needed by the skin to make vitamin D. It can be used to kill bacteria.

Ultraviolet radiation

Type of electromagnetic radiation with lowest frequency and longest wavelength; used in Wi-Fi, radio, radar, and television.

radio waves

Which is higher in energy, infrared waves or ultraviolet waves?

ultraviolet

Find the wavelength of a wave in meters whose speed is 60 m/s and whose frequency is 2 Hz.

30 m

Find the frequency of a wave whose wavelength is 4 m and speed is 20 m/s.

5 Hz

Calculate the wavelength of electromagnetic radiation if the frequency is 6.10 x 10¹⁴Hz? The speed of light is 3.0 x 10⁸ m/s.

4.9 x 10⁻⁷ m

What are x-rays?

type of electromagnetic waves used for medical imaging; higher in energy and shorter wavelength than ultraviolet

Type of electromagnetic radiation used by remote controls

infrared

Type of electromagnetic radiation used by GPS satellites and doppler radar

microwaves

How does the speed of visible light compare to ultraviolet light?

they have the same speed

How does the speed of visible light compare with the speed of gamma rays, when both speeds are measured in a vacuum?

they have the same speed

What happens to the speed of light when light passes through a medium such as glass?

the speed is slower

What does AM stand for?

amplitude modulation

What does FM stand for?

Frequency Modulation

How does analog signal compare to digital signal?

Analog signal is a continuous signal which represents physical measurements. Digital signals are discrete time signals generated by digital modulation.

What is the energy of a long wavelength wave?

low energy

What is the energy of a high frequency wave?

high energy

Does red light or yellow light have a longer wavelength?

red light

What is the wavelength of a wave?

the distance between two of the same points on a wave

What is resonance?

the response of a standing wave to another wave of the same frequency

Hearing damage may occur in humans if they are excessively exposed to noise above:

90 dB

Sounds at this level cause pain and damage to your hearing

120 dB

The process of adding an information signal to a carrier radio wave is called__.

modulation

A system of orbiting satellites, ground monitoring stations, and receivers that determine an exact location on Earth by sending microwave signals.

Global Positioning System

The unit of frequency is \_____.

Hertz (Hz)

Unit of speed

meters per second (m/s)

unit of wavelength

meters (m)

Sound is an example of what kind of wave?

longitudinal wave

What is a vacuum?

an empty space with no particles and no pressure; no medium

The law of reflection states

the angle of incidence is equal to the angle of reflection

An echo occurs when sound

is reflected from a surface

How close together the particles of the medium are in the compressions of a longitudinal wave determines which property of the wave?

amplitude

Which type of electromagnetic waves cause you to feel warmer when you stand near a fire?

infrared

Which type of electromagnetic waves have the highest energy?

gamma rays

Which is the term for an electromagnetic wave with the specific frequency that a radio station is assigned?

carrier wave

Which best describes the function of a transceiver?

transmits and receives signals

How can you prevent damage to the hair cells of the cochlea of your ears?

Avoid loud music and wear earplugs when exposed to sounds that are 90 dB or greater such as gunshots and workplace noise

Calculate the wave speed for a wave with a wavelength of 2 m and a frequency of 0.3 Hz.

0.6 m/s

unit of sound intensity

decibel (dB)

Does light travel faster in air or water?

air

Does sound travel faster in air or water?

water