Theme C Flashcards
What is the amplitude
The maximum displacement from an oscillation
What is the period, T
The time required for the position and velocity of the object to repeat
What is frequency, f
The number of oscillations completed per
unit time. (seconds)
Define simple harmonic motion
When the restoring acceleration is proportional to the displacement from the equilibrium and in the opposite direction
State the equation for a simple harmonic oscillator
Where:
a = acceleration
ω = angular frequency
x = displacement from equilibrium
Where:
T = period
f = frequency
ω = angular frequency
Characteristics of harmonic oscillator
- Period constant
- Amplitude constant
- Isochronous
- position, velocity, acceleration are sinusoidal functions of time
State the period of harmonic oscillation of a spring
Where:
T = period
m = mass
k = spring constant
g would not affect the period and only the equilibrium position
State the period of harmonic oscillation of a pendulum
Where:
T = period
l = length of string
g = acceleration of free fall
the period is independent of the mass
Comment on the energy within oscillatory motion
The energy of the system itself
oscillates between potential and kinetic.
The energy oscillates with a frequency twice that of the system’s oscillation’s.
Differentiate between transverse and longitudinal waves
Transverse: The disturbance of the wave is perpendicular to the direction of propagation
Longitudinal: The disturbance of the wave is parallel to the direction of propagation
Define wavelength
Length of one repeating section
State the equation for wave speed
Where:
v = wavespeed
f = frequency
λ = wavelength
T = period
What are compressions and rarefactions in longitudinal mechanical waves
Compression is where the medium is pushed together and rarefaction is where the medium is pulled apart
Wavefronts
Continuous surfaces on a wave separated by a wavelength
Rays
Arrows which show the direction of propagation
Relationship between wavefronts and waves
perpendicular
Define intensity, I
Power delivered per unit area to a surface
Relationship between intensity and amplitude
Intensity is often proportional to the square of the amplitude of the wave
Relationship between intensity and distance from the source
Inversley proportional to the square of the distance from the source
What is diffraction
The ends of the wave fronts spread out
What angles do waves get reflected towards
Same angle on the opposite side of the normal
When is a reflected wave flipped
When the incident wave is traveling into a medium which resists oscillations more
What is refraction
When the transmitted wave propagates at a different angle from the normal because the wave speeds of the two mediums are different
What is the refractive index, n
The ratio of the speed of light in a vacuum, c, to the speed of an electromagnetic wave in a medium, v.
Refractive index of air is 1.
When will electromagnetic waves be flipped when reflected
When the wave is incident on a medium of higher refractive index
State snells law
where:
n = refractive index
theta = angle between the ray and the normal
v = wavespeed in one medium
Under what conditions does total internal reflection occur
If v2 > v1, or equivalently n2 > n1, then there are possible angles of incident θ1 such that there are no real solutions for θ2.
What is the critical angle
The largest angle of incidence before total internal reflection occurs
Constructive and destructive interference
What are coherent waves
waves with identical frequency and wavelengths
Complete constructive and complete destructive interference formula
State the formula for double slit interference
Where:
s = spacing of the bands
λ = wavelength of the interfering wave
D = distance between the double slits and the detector screen
d = separation of the two slits.
