waves

Question 1

what is the wave equation?
WAVES

Answer 1

c = f x λ

where:
• c = speed of wave
• f = frequency of wave
• λ = wavelength of wave

Question 2

what is the equation for frequency, using: f and T?
WAVES

Answer 2

f = 1 / T

where:
• f = frequency of wave
• T = time period of wave

Question 3

what is the equation for the frequency of the first harmonic when talking about a wave on a string, using: L, T and m?
WAVES / SHM

Answer 3

f = (1/ 2L)√(T / μ)

where:
• L = length of string
• T = tension of string (T usually = weight of string, mg)
• μ = mass per unit length of string

Question 4

what is the equation for fringe spacing using young’s double slit, using: x, λ, L and d?
WAVES

Answer 4

x = λL / d

where:
• x = fringe spacing
• λ = wavelength of wave
• L = distance or length from slit to screen
• d = slit spacing

Question 5

what is the equation for angle of diffraction when using diffraction grating, using: d, θ, n, λ?
WAVES

Answer 5

nλ = dsinθ

where:
• d = slit spacing
• θ = angle of diffraction (or angle of order)
• n = order number of fringe (eg, first order, second order)
• λ = wavelength of wave

Question 6

what is the equation for slit (or grating) spacing (distance between slits) when using diffraction grating?
WAVES

Answer 6

d = 1 / lines per m

Question 7

what is the equation for refractive index?
WAVES

Answer 7

n = c / cs
or
n = c / v

where:
• c = speed of light in vacuum
• cs or v = speed of light in medium

Question 8

what is the equation for snell’s law?
WAVES

Answer 8

n1sinθ1 = n2sinθ2

where:
• n1 = refractive index of 1st medium
• sinθ1 = angle of incidence
• n2 = refractive index of 2nd medium
• sinθ2 = angle of refraction

Question 9

what is the equation for the critical angle?
WAVES

Answer 9

sinθc = n2 / n1

where:
• sinθc = the critical angle
• n1 = the refractive index of the 1st medium
• n2 = the refractive index of the 2nd medium