-
the line joinig the object to the image is at
right angles to the mirror
-
the image in the plane mirror is
laterally inverted
-
the image in the plane mirror is ....... and the same sizes as the object
virtual
-
the image is as far behind the mirror as
is in front
-
....... are examples of sound being reflected
echoes
-
what is refraction
it is when rays of light direction when they cross the boundary between two one trasnparent substance and an another
-
if a light waves hits a bounday face on it : i.e. if the ray meets the boundary ar right angles (along the normal)
carries on in the same direction i.e. it does not refract
-
if a wave meets a different medium at an angle the wave
changes direction - it has been refracted
-
light travels more slowly in glass , as the light is slowed down it changes direction and is refracted ........ the normal
towards
-
when light leaves glass , it speeds up and is refracted ...... from the normal
away
-
in refrcation the angel of incidence =
the angel of the emergant ray if the block is rectangular
-
the angel of inciendence is ..... than the angel of refraction
larger
-
refraction the incident ray should be ......... to the emergant ray if the block is regtangular
parralel
-
tagaga
- towards (towards the normal) air -> glass
- away (from the normal) glass -> air
-
what happens to the speed of the light ray when it passes from glass to air
it increases
-
sound waves travel through solids , liquids , and gases as ...... waves
longitudinal
-
sound waves travel ..... ... than light waves
more slowly
-
sound are produced when
obejcts vibrate
-
sound waves ....... travel through a vacuum
cannot
-
the higher the frequency the
higher the pitch
-
the bigger the amplitude the
louder the sound
-
most children can hear sounds in the range from about
20 Hz to 20,000 Hz
-
diffraction happens
when a wave meets a gap in a barrier or an obstacle , they carry on through the gap , however , the waves spread out to some extent into the area beyond the gap . this is called diffraction
-
wide gap = ......... diffraction effect
small
-
narrow gap = ...... diffraction effect
large
-
large wavelength = .....
diffraction
-
significant diffraction only occurs when
the wavelength of the wave is of same size as the width of the gap or size of the obstacle
-
what doesnt change when a wave is diffracted
the speed and wavelength of the wave
-
how many hertz is a kilohertz
1,000
-
how many hertz is a mega hertz
1,000,000 hertz
-
how many hertz is a gigahertz
1,000,000,000 hertz
-
wave speed is measured in
metres per second m/s
-
frequency is measured in
hertz , Hz
-
wavelength is measured in
metres , m
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