Waves Flashcards
Which wave in the electromagnetic spectrum has the shortest wavelength?
Gamma rays have the shortest wavelength.
The diagram shows what would happen if waves of a short wavelength approach an obstacle.
What would be observed if the waves had a long wavelength?
Long wavelengths diffract more than short wavelengths.
Therefore the waves would bend around the obstacle more.
What does the prefix m stand for?
m stands for milli
milli = x 10-3
Describe what is meant by gamma radiation.
- Gamma radiation is a wave in the electromagnetic spectrum
- Gamma rays have no mass or charge
- Gamma rays have a very short wavelength and a high frequency
What happens to the speed of a ray of light as it goes from glass into air?
As a ray of light goes from glass into air, its speed increases.
(the light speeds up in a medium which is less optically dense)
What does the prefix G stand for?
G stands for giga
giga = x 109
What is the unit for period?
(period of a wave)
The unit for period is seconds (s)
What does the prefix n stand for?
n stands for nano
nano = x 10-9
What type of wave is a water wave an example of?
A water wave is an example of a transverse wave.
What is being shown in this diagram?
This is diffraction - the bending of waves around an obstacle.
What is the unit for wavelength?
The unit for wavelength is metres (m)
Give one application of radio waves.
- Broadcasting
- Satellite transmissions
- Communications
Give one use of visible light.
- photography
- illumination
- car headlights
- street lighting
Give one use of gamma rays.
- sterilising food and medical equipment
- treating cancer
- medical tracers
State one source of visible light.
Sources of visible light include:
- the Sun
- light bulbs
- anything hot enough to glow
What type of wave is a sound wave an example of?
A sound wave is an example of a longitudinal wave.
What is meant by the wavelength of a wave?
Wavelength is the distance between a point on one wave and the same point on the next wave.
Give one use of X-rays.
- medical X-ray scans
- airport security scanners
Does a ray of light always change direction when it undergoes refraction?
No - not always. A ray of light which enters a material at 90° to the surface will not change direction.
(e.g. middle ray in diagram)
Name the three quantities shown in this formula.
v = speed
f = frequency
λ = wavelength
(λ is called ‘lambda’)
Which wave in the electromagnetic spectrum has the longest wavelength?
Radio waves have the longest wavelength.
What is the unit for speed?
The unit for speed is metres per second (ms-1)
Name the three quantities shown in this formula.
d = distance
v = speed
t = time
A ray of light exits a block of glass (as shown). Describe the path of the ray of light after it exits the glass.
The ray of light bends away from the normal as it exits the glass.
In the diagram shown, what is the dotted line and what is important about where it is?
The dotted line is the normal.
The normal is at 90° to the surface of the medium.
Name the two quantities shown in this formula.
T = period
f = frequency
From the diagram shown, identify the wavelength of the wave.
C is the wavelength.
From the diagram shown, identify the amplitude of the wave.
D is the amplitude.
In the diagram shown, what do the symbols i and r represent?
i = angle of incidence
r = angle of refraction
A ray of light enters a block of glass (as shown). Describe the path of the ray of light after it enters the glass.
The ray of light will bend towards the normal as it enters the glass.
