Waves Flashcards
1
Q
Wave Function
A
U(x,t) = A cos(± kx −ωt)
2
Q
Wave Number Equation
A
k = 2π/λ
3
Q
Angular Frequency Equation
A
ω = 2π/T
4
Q
Wave Speed Equation
A
- c
- =fλ
- =ω/k
5
Q
Wave Equation
A
(∂^2 U)/(∂T^2 )= c^2 (∂^2 U)/(∂x^2 )
6
Q
Group Velocity Equation
A
v = dω/dk
7
Q
Phase Velocity Equation
A
v = ω/k
8
Q
Dispersive wave conditions
A
- group velocity = phase velocity : non-dispersive
- group velocity ≠ phase velocity : dispersive
9
Q
Wave speed through a string equation
A
- c^2 = T/μ
- c is wave speed
- T is tension
- μ is mass per unit length
10
Q
Doppler Effect equation (EM)
A
- f’ = f * ((c-v)/(c+v))^1/2
- f’ is observed frequency
- v is speed of observer + source
11
Q
Doppler Effect equation (sound)
A
- f’ = f * (c+u0)/(c+uS)
- f’ is observed frequency
- u0 is observer speed
- uS is source speed
12
Q
Refractive Index Equation
A
n = c/v
13
Q
Snell’s Law
A
n1sinθ1 = n2sinθ2
14
Q
Total Internal Reflection Conditions
A
- High n to Low n
- Critical Angle = arcsin(n1/n2)
15
Q
Transmission Equation
A
(4n1n2)/(n1+n2)^2
