AS2 Equations

Question 1

Wave equation

Answer 1

V = f x lambda

Question 2

Frequency/Time Period Equation

Answer 2

f = 1/T

Question 3

Phase Difference Equation

Answer 3

ϕ = X / λ x 360 °

ϕ = t / T x 360 °

Question 4

Refractive Index Equations (3 of them)

Answer 4

1n2 = c1 / c2
1n2 = 1 / 2n1
n = sini / sinr

Question 5

Total Internal Reflection Equation (Critical Angle)

Answer 5

sinC = 1 / n
C = Critical Angle
N = refractive Index

Question 6

Focal Length Equation

Answer 6

1 / u + 1 / v = 1 / f
u being object distance
v being image distance
f being focal length

Question 7

Magnification Equation

Answer 7

M = v / u
M = hi / ho
M being Magnification
v being image distance
u being object distance
hi being image height
ho being object height

Question 8

Power Equation

Answer 8

p = 1 / f
(f must be in metres)
p = power (dioptres)
f = focal length

Question 9

Double Slit Diffraction Equation 1 (normal one)

Answer 9

λ = ay / d

a is slit separation (left distance)
λ is light wavelength
d is distance from double slit to screen (big distance)
y is inteference fringe separation (right distance)
EVERYTHING MUST BE IN METRES

Question 10

Double Slit Diffraction Equation 2 (sin one)

Answer 10

nλ = dsinθ
d is distance between slits (left distance)
θ is angle between maxima and central maxima
n is order number of maximum
λ is wavelength of light

Question 11

Double Slit Diffraction Equation 3 (order maximum)

Answer 11

n = d / λ
n is order number of maximum
d is distance between slits (left distance)
λ is wavelength of light
MUST BE ROUNDED DOWN e.g 1.8 = 1

Question 12

Diffraction Grating Equation

Answer 12

number of lines per metre = 1 / distance between grating slits

Question 13

Photon Energy Equation

Answer 13

E = h x f
E being energy of photon
h being plancks constant (6.63x10^-34)
f being frequency

Question 14

Photoelectric Effect Equations

Answer 14

E (of photon) = ϕ + KE (electron max)
ϕ is work function

hf = hfo + 1/2m(electron)v^2 (max)
h being plancks constant
fo being threshold frequency

Question 15

Energy Levels Equation

Answer 15

△E = hf
△E being change in energy
h being plancks constant
f being frequency

Question 16

De Broglie Wavelength Equation

Answer 16

λ = h / p
h being plancks constant
p being momentum (m x v)

Question 17

Doppler Shift Equation (λ one)

Answer 17

λ = (1 + vs / vw) x λ0
λ being apparent/observed wavelength
Vs being the velocity of the source relative to the medium
Vw being the velocity of the waves in the medium
λ0 being the wavelength emitted from the source

Question 18

Doppler Shift Equation (f one)

Answer 18

f = (Vw / Vw + vs) x f0
f = apparent/observed frequency
Vw being velocity of waves in the medium
Vs being velocity of the source relative to the medium
f0 being the frequency emitted from the source

Question 19

Red Shift Parameter Equations

Answer 19

z = △λ / λ0
z = △f / f0
z = Vs / c

△λ is λ - λ0
f0 is emitted frequency
△f is difference between emitted and observed frequency
λ0 is emitted wavelength
△λ is the difference between emitted and observed wavelength
Vs is the velocity of the source in the observers direction
C is the usual speed of the waves in that medium ( speed of light)

Question 20

Hubble’s Law Equation

Answer 20

v = Ho x d

v is the recessional velocity
Ho is hubble’s constant (2.4x10^-18)
d = distance between Earth and the galaxy in question

Question 21

Age of the Universe Equation

Answer 21

T = 1 / Ho
T being age of universe
Ho being Hubble’s Constant or Parameter
(2.4x10^-18)