Notes - Fisika - Radiasi

Radiasi Benda Hitam

P=e*σ*A*T4

T, Temperature, T=(T_C)+273

(A_), Area

e, Emisivitas 0≤e≤1

σ=5.67⋅10(-8), Boltzmann constant

Light is a wave.

c=ƒ*λ

c=3⋅108, the speed of light (m/s)

ƒ, Frequency (Hz)

λ, Wavelength (m)

Ex. 1

P=0.8⋅5.67⋅10(-8)⋅(10⋅10(-2))2⋅(727+273)4=2268/5=453.6

Ex. 2

32=x⋅(127+273)4

x=1/800000000

P=1/800000000⋅(327+273)4=162

Ex. 3

(I_S)=1400⋅((1.5⋅1011)/(7⋅108))2=450000000/7=64285714.28

(I_S)=5.67⋅10(-8)⋅T4

T4=64285714.28/(5.67⋅10(-8))

T=5802.736551281401

Ex. 4

E=5.67⋅10(-8)⋅0.5⋅2⋅10(-6)⋅1004⋅10

E=567/10000000=567⋅10(-7)=5.67⋅10(-5)

Ex. 5

3.6⋅1026=6⋅1016⋅5.67⋅10(-8)⋅1⋅T4

T=√(4,(3.6⋅1026)/(6⋅1016⋅5.67⋅10(-8)))=20000/21*53/4√(4,1029)

Wien

t⋅λ=C

The hotter a black body is, the smaller the wavelength emitted.

C=2.9⋅10(-3), the Wien constant

T, Temperature

Plancke

E=h*ƒ=(h*c)/λ

E, Energy of a Singular Photon

h=6.6⋅10(-34), Plancke's Constant

Compton

E=h⋅c/λ

(E^′)=h⋅c/(λ^′)

Δ(λ)=(λ^′)-λ

Δ(λ)=h/(m⋅c)⋅cos(θ)

m=9.1⋅10

c=3⋅10

(E_k)=E-(E^′)=1/2*m*v2

Problem 1

Δ(λ)=(2.43⋅10)/(9.1⋅10⋅3⋅10)⋅1/2=0,0012

λ=0.2-0.0012=0.1988

Problem 2

λ=0.035=3.5⋅10

θ=37

Δ(λ)=(6.6⋅10)/(9.1⋅10⋅3⋅10)⋅(1-4/5)
=4.835⋅10

(λ^′)=4.835⋅10+3.5⋅10=3.54⋅10

(E^′)=6.6⋅10⋅(3⋅10)/(3.54⋅10)=5.59⋅10

(E_k)=6.6⋅10⋅(3⋅10)/(3.5⋅10)-5.59⋅10=6.71⋅10

Problem 3

λ=1⋅10

θ=90

∴Δ(λ)=(6.6⋅10)/(9.1⋅10⋅3⋅10)⋅(1-cos(90))=2.42⋅10

(λ^′)=2.42⋅10+1⋅10=1.02⋅10

(E_k)=6.6⋅10⋅3⋅10⋅(1/(1⋅10)-1/(1.02⋅10))=3.88⋅10

3.88⋅10=1/2⋅