Waves Flashcards
What are the roles of waves
Transfer energy from one place to another
How to waves move
They Oscillate
What is the time period of a wave
The time it takes for one complete oscillation
Wave speed formula
Wave speed = Frequency x wavelength
Transverse wave movement
Oscillations are perpendicular to the direction of energy transfer
Examples of transverse waves
Light waves, physical waves
Longitudinal waves movement
Oscillations that are parallel to the direction of energy transfer
Longitudinal waves example
Sound waves and seismic waves
In reflection, angle of i = ?
Angle of incidence = angle of reflection
What is the normal
A line perpendicular from the surface
What is specular reflection
When the surface is flat and the normals are all in the same direction creating a clear image e.g. mirrors
What is scattered reflection
The surface is bumpy, normals are all different meaning we can’t see ourselves in the reflection
What is refraction
When waves change direction as they pass from a medium to new medium e.g. air into glass
What direction does the wave go when it enters a higher medium
The wave direction goes towards the normal
What direction does wave go when entering higher medium in a straight line
Continues in a straight line
What is the first step when drawing a ray diagram
Draw the normal at the point of incidence
What is the ray called in the more dense medium
Refracted ray
When ray goes from denser medium to less dense medium, what happens
It speeds up and bends away from the normal
What happens when white light is put through a triangular prism
The different colours of the rainbow bend at different degrees as they have different wave lengths
What is the law of refraction
When a wave enters a new medium, it changes direction
Law of reflection
Angle of incidence = angle of reflection
What are the conditions needed to TIR (Total internal reflection)
Angle of incidence > critical angle
-Going from a high refractive index to a low refractive index
Use of total internal reflection
Used in optical fibers
Used in cameras during keyhole surgery
What is the critical angle
The angle of incidence when the ray of refraction is 90 degrees, the ray causes TIR.
