waves

Question 1

what is a mechanical wave

Answer 1

wave
must travel through substance ( medium)

examples: sound waves,seismic waves

Question 2

what is an electromagnetic wave

Answer 2

a wave
don’t need to travel through medium (can travel through vacuum)

examples: light waves, radio waves, microwaves

KNOWN AS THE ELECTROMAGNETIC SPECTRUM

Question 3

how fast do electromagnetic waves travel

Answer 3

300,000km per second

Question 4

what is a transverse wave

Answer 4

a wave
vibration at right angles to the energy transfer

eg light

Question 5

what is a longitudinal wave

Answer 5

the vibrations
parrollel to the energy transfer

eg sound

Question 6

what is the amplitude of a wave

Answer 6

height of wave crest or depth of wave trough

Question 7

what is the peak of a wave

Answer 7

the highest point of the wave

Question 8

what is the trough of a wave

Answer 8

the lowest point of a wave

Question 9

what is oscillation

Answer 9

the distance between the peak and the trough

Question 10

what is the wavelength

Answer 10

the distance between 2 peaks or 2 troughs

Question 11

what is a compression

Answer 11

when the wave lengths are very close together (high pressure)

Question 12

what is a rarefaction

Answer 12

where the waves lengths are far from eachother ( low pressure)

Question 13

what are waves

Answer 13

vibrations

transfer energy from place to place without matter being transferred

Question 14

what is the frequency of a wave

Answer 14

the number of waves produced/pass by a source each second

measured in Hz (hertz)

Question 15

what’s the human hearing range in Hz

Answer 15

20Hz to 20,000Hz

Question 16

what is the period of a wave

Answer 16

the time taken for one wave to be produced/pass a point

measured in seconds

Question 17

what is a wavefront

Answer 17

the lines we draw to represent the vibrating part of a wave

)))))))

Question 18

what is diffraction

Answer 18

when the wave meets a gap but spread out to some extent beyond the gap

Question 19

what does the extent of the diffraction depend on

Answer 19

on how the width of the gap compares to the wavelength of the waves

Question 20

what would create a significant diffraction

Answer 20

large wavelength and a narrow gap

eg sound through a doorway

Question 21

what would create little diffraction

Answer 21

wide gap with small wavelength

eg light through a doorway

Question 22

how does the wavelength change with diffraction

Answer 22

the wavelength doesn’t change with diffraction

Question 23

what is the wave equation

Answer 23

speed (m/s) = frequency (Hz) x wavelength (m)

v= f x /\

Question 24

what is 1kHz and 1mHz equivalent to in Hz

Answer 24

1kHz= 1,000Hz

1mHz= 1,000,000Hz

Question 25

how do you work out the frequency of a wave

Answer 25

frequency= 1
————
Time Period

time period is the time it takes to complete 1 oscillation (measured in seconds)

Question 26

what do we use waves for

Answer 26

to transfer energy and information

Question 27

what happens to the air particles when a sound wave passes through the the air

Answer 27

makes vibrations

compressions (close together) and rarefactions (spread out)

Question 28

why might someone gave bad signal if they live near hills

Answer 28

if the radio waves don’t diffract enough