Waves - AS91170 Flashcards
Convex Mirrors
Diverge and have a negative focal length
Will always be virtual, upright, diminished
Focal is ‘inside’ mirror - for ray diagram
Concave Mirrors
Converge and have a positive focal length
What is refraction?
It is the bending of a waver when it passes from medium to another
What is refraction caused by?
A change in the speed of the wave. Frequency does not change, a change in wavelength occurs.
When will a wave bend away from the normal?
More dense to a less dense medium, the light wave speeds up and bends away from the normal.
Less dense to a more dense medium the light wave slows down and bends toward the normal. The greater the angle of incidence the larger the angle of refraction.
What must occur for Total Internal Reflection to occur?
Light travels from a more dense medium to a less dense medium (where there is a critical angle at which the angle of refraction is 90*)
- The angle of incidence must be large than the critical angle ( so all of the light is being reflection back - not refracted)
Concave Lenses
Diverge and focal is negative
Will always be virtual, upright, diminished
Convex Lenses
Converge and focal is positive
Longitudinal Waves
Particles vibrate parallel to the direction of motion of the wave
Transverse Waves
Particles vibrate perpendicular to the direction of motion of the wave
Period
T
Heavy string to light string
Pulse travels quickly + reflected pulse
Light to heavy string
Upside down reflected pulse + smaller pulse
Superposition
The ability of waves to add their displacements and energy as they move through each other
Constructive Interference
Results if the two waves are added together to form a maximum amplitude (collide)
Adds
