Waves Flashcards
What are the two types of wave
Longitudinal
Transverse
What is a transverse wave
Oscillations are perpendicular to direction of energy transfer
What is a longitudinal wave
Oscillations are parallel to energy transfer
Example of transverse waves
Electromagnetic waves
Seismic waves S waves a
Examples of longitudinal
Sound waves
Seismic P waves
Two parts of a longitudinal wave called
Compressions and rarefactions
What is the frequency of a wave
The number of waves that pass a given point per second
How does sound waves travel through solid
Particles in solid vibrate and transfer kinetic energy through material
What produces seismic waves
Earthquakes
What’s a difference between P waves and S waves
P waves travel through solids and liquids
S waves only travel through solids
Electromagnetic radiation ordered
Radio waves
Micorowaves
Infrared
Visible light
Uv
X-rays
Gamma rays
What do waves do when entering a denser medium
Bend towards normal
What health effects can X-rays and gamma rays cause
Mutations in genes as they are ionising radiation
Cancer
What is meant by the focal length of a lens
Distance from lens’s to principal focus
What determines colour of visible light waves
Frequency and wavelength
What do all objects emit and absorb
Infrared radiation
What is perfect black body
An object that absorbs all radiation
Two factors that effect temp of earth
Rate of absorption and emission of radiation
What’s the difference between concave and convex lens
Convex have larger focal length
How does a loudspeaker work
Electrical signal sent to voice coil
Create a magnetic field that interacts with the magnetic field of permanent magnet
Causes the voice coil to move back and forth
Causes diaphragm to vibrate
What does it mean If there is a large amplitude
Louder
Advantages of ultrasound over x-rays
Doesn’t cause gene mutations /cancer
How to sound waves travel
Vibration of particles
What is the frequency of an ultrasound?
20000hz+
