P1.5 Flashcards
What is an oscillation?
A vibration
What are longitudinal waves for?
Sound
What is the makeup of longitudinal waves? How do they move?
The vibration goes in the same direction as energy, In a straight line with compressions and rare-fractions.
What are transverse waves for?
Light (all electromagnets)
What is the makeup of transverse waves? How do they move?
The vibrations goes perpendicular to the direction of the energy in peaks and troughs.
What is the wave equation?
Wave Speed(m/s)= Frequency(Hz) x Wave length(m)
What is the speed of light?
3 x 10(8) = 300,000,000
What is the electromagnetic spectrum?
Radiowaves, Microwaves, Infrared radiation, Visible light, Ultraviolet, X rays, Gamma rays
What are the colours in visible light?
Red, Orange, Yellow, Green, Blue, Indigo, Violet
Which 3 in the electromagnetic spectrum can damage DNA in cells?
Ultraviolet, x rays and gamma rays
At what speed do all of the electromagnetic spectrum travel at?
At speed of light = 3 x 10(8)
What is the use of radiowaves?
TV Signals
What is the use of microwaves?
Heating food, phone communication
What is the use of Infrared radiation?
Remote controls
What is the use of Ultraviolet?
Sun tan, detect forgery
What is the use of x rays?
Broken bones, hidden bombs
What is the use of gamma rays?
Kill cancerous cells
What is the law of reflection?
Angle of incidence = angle of reflection
What happens when light travels from a space of low density to a space of high density?
The angle of reflection moves towards the normal
Expain diffraction
Diffraction occurs when a wave passes an edge or passes through a narrow gap or goes past an object.
None of the properties of a wave are changed by diffraction, but the direction of the wave is changed to go between the gap or obstacle.
Explain refraction
Refraction occurs when a wave moves from one material to another, as the light speeds up and passes through the different materials, the angle of refraction is bigger than the angle of incidence.
If the frequency of a sound is high, then what is the pitch?
High
If the frequency of a sound is low, then what is the pitch?
Low
What is the doppler effect?
The apparent change in the frequency of a wave caused by the relative motion of the source and the observer. (when a sound coming towards you sounds louder than it actually is)
Where is the doppler effect used?
There are doppler scans in medicine to measure how fast an unborn baby’s blood flows, and in speed cameras.
What is redshift?
Where an object coming towards you looks more red and an object moving away from you looks more blue than it really is.
What did Sir Fred Hoyle believe about creation?
STEADY SLATE: He believes that the universe had no start and would always be the same
What does Steven Hawking believe about creation?
THE BIG BANG THEORY: He believes that the universe had a definite beginning from a small point, and is constantly expanding.
What is CMBR?
Cosmic Microwave Background Radiation - When the Big Bang happened, there were loads of infrared radiation which stretched to turn into microwaves.
Give some possible evidence to support the Big Bang Theory
Red shift could support it as stars in our atmosphere appear red tinted which means that they are moving away from us so they must have started close together.
