Topic 5- Waves Flashcards
What is displacement?
The position of a particular point on a wave, at a particular instant in time, measured from the mean.
What is amplitude?
The magnitude of the maximum displacement, reached by an ocscillation in the wave.
What is frequency?
The number of complete wave cycles per second.
What is wavelength?
The distance from any point on a wave to an identical point on the next cycle of wave.
Define period?
The time required to complete one cycle of a wave.
What is a phase?
The stage a given point on a wave is through a complete cycle. Measured in angle units.
Define wave speed?
The rate of movement of the wave, measured in m/s
Equation that links, wave speed, frequency, and wavelength.
Wave speed=frequency x wavelength
Equation that links, time period and frequency?
Frequency = 1/time period
Are sound waves longitudinal or transverse?
Sound waves are longitudinal, so oscillations occur parallel to the direction of movement.
What is compression?
Area in longitudinal waves where the particle oscillations put them closer to each other than their equilibrium state.
What is a wavefront?
The difference between two peaks (highest point on a wave) or two troughs (lowest point on a wave). Drawn as lines.
What is constructive interference?
Where two waves arrive in step reinforcing one another (increasing the amplitude)
What is destructive interference?
Where two waves arrive out of phase (exactly 180°) cancelling one another out.
What is a stationary wave?
A stationary wave consists of oscillations in a fixed space, with reigons of significant oscillation, and regions with 0 oscillations.
When are waves coherent?
Waves are coherent if they have the same frequency and a constant phase relationship.
What are nodes?
Reigons on a stationary wave where the amplitude of oscillation is 0.
What is superposition?
The adding together of wave displacements that occurs when waves from 2 or more separate sources overlap. They add together.
What’s coherence?
Same frequency and wavelength and a fixed phase difference.
What kind of image is created if the object is more than one focal length away from the lens?
Real
What kind of image is created if the object is less than one focal length away from the lens?
Virtual
What is the critical angle?
The angle of incidence when the angle of refraction is 90 degrees, and all light passes along the boundary between the mediums.
What happens when the angle of incidence is above the critical angle?
All light is reflected.
What is total internal reflection?
Total internal reflection is where all the light is reflected inside a material, it occurs when the angles of incidence is greater than the critical angle.
