The Compton Shift [tex]\Delta \lambda[/tex] in wavelength when the photons are scattered is given by the following equation:
[tex]\Delta \lambda=\lambda' - \lambda_{o}=\lambda_{c}(1-cos\theta)[/tex] (1)
Where:
[tex]\lambda_{c}=2.43(10)^{-12} m[/tex] is a constant whose value is given by [tex]\frac{h}{m_{e}.c}[/tex], being [tex]h=4.136(10)^{-15}eV.s[/tex] the Planck constant, [tex]m_{e}[/tex] the mass of the electron and [tex]c=3(10)^{8}m/s[/tex] the speed of light in vacuum.
[tex]\theta=41\°[/tex] the angle between incident phhoton and the scatered photon.
We are told the scattered X-rays (photons) are deflected at [tex]41\°[/tex]:
[tex]\Delta \lambda=\lambda' - \lambda_{o}=\lambda_{c}(1-cos(41\°))[/tex] (2)
[tex]\Delta \lambda=\lambda' - \lambda_{o}=5.950(10)^{-13}m[/tex] (3)
But we are asked to express this in [tex]nm[/tex], so:
[tex]\Delta \lambda=5.950(10)^{-13}m.\frac{1nm}{(10)^{-9}m}[/tex]
[tex]\Delta \lambda=0.000595nm[/tex] (4)
(b) the energy of the scattered x-rayThe initial energy [tex]E_{o}=265keV=265(10)^{3}eV[/tex] of the photon is given by:
[tex]E_{o}=\frac{h.c}{\lambda_{o}}[/tex] (5)
From this equation (5) we can find the value of [tex]\lambda_{o}[/tex]:
[tex]\lambda_{o}=\frac{h.c}{E_{o}}[/tex] (6)
[tex]\lambda_{o}=\frac{(4.136(10)^{-15}eV.s)(3(10)^{8}m/s)}{265(10)^{3}eV}[/tex]
[tex]\lambda_{o}=4.682(10)^{-12}m[/tex] (7)
Knowing the value of [tex]\Delta \lambda[/tex] and [tex]\lambda_{o}[/tex], let's find [tex]\lambda'[/tex]:
[tex]\Delta \lambda=\lambda' - \lambda_{o}[/tex]
Then:
[tex]\lambda'=\Delta \lambda+\lambda_{o}[/tex] (8)
[tex]\lambda'=5.950(10)^{-13}m+4.682(10)^{-12}m[/tex]
[tex]\lambda'=5.277(10)^{-12}m[/tex] (9)
Knowing the wavelength of the scattered photon [tex]\lambda'[/tex] , we can find its energy [tex]E'[/tex] :
[tex]E'=\frac{h.c}{\lambda'}[/tex] (10)
[tex]E'=\frac{(4.136(10)^{-15}eV.s)(3(10)^{8}m/s)}{5.277(10)^{-12}m}[/tex]
[tex]E'=235.121keV[/tex] (11) This is the energy of the scattered photon
(c) Kinetic energy of the recoiling electron
If we want to know the kinetic energy of the recoiling electron [tex]E_{e}[/tex], we have to calculate all the energy lost by the photon in the wavelength shift, which is:
[tex]K_{e}=E_{o}-E'[/tex] (12)
[tex]K_{e}=265keV-235.121keV[/tex]
Finally we obtain the kinetic energy of the recoiling electron:
[tex]E_{e}=29.878keV[/tex]
Answer:
The first one:
the energy of the scattered x-ray
The answer for last on:
Kinetic energy of the recoiling electron
4.5 cm3 of water is boiled at atmospheric pressure to become 4048.3 cm3 of steam, also at atmospheric pressure. Calculate the work done by the gas during this process. The latent heat of vaporization of water is 2.26 × 106 J/kg . Answer in units of J. 006 (part 2 of 3) 10.0 points Find the amount of heat added to the water to accomplish this process. Answer in units of J.
1. 408.4 J
The work done by a gas is given by:
[tex]W=p\Delta V[/tex]
where
p is the gas pressure
[tex]\Delta V[/tex] is the change in volume of the gas
In this problem,
[tex]p=1.01\cdot 10^5 Pa[/tex] (atmospheric pressure)
[tex]\Delta V=4048.3 cm^3 - 4.5 cm^3 =4043.8 cm^3 = 4043.8 \cdot 10^{-6}m^3[/tex] is the change in volume
So, the work done is
[tex]W=(1.01\cdot 10^5 Pa)(4043.8 \cdot 10^{-6}m^3)=408.4 J[/tex]
2. 10170 J
The amount of heat added to the water to completely boil it is equal to the latent heat of vaporization:
[tex]Q = m \lambda_v[/tex]
where
m is the mass of the water
[tex]\lambda_v = 2.26\cdot 10^6 J/kg[/tex] is the specific latent heat of vaporization
The initial volume of water is
[tex]V_i = 4.5 cm^3 = 4.5\cdot 10^{-6}m^3[/tex]
and the water density is
[tex]\rho = 1000 kg/m^3[/tex]
So the water mass is
[tex]m=\rho V_i = (1000 kg/m^3)(4.5\cdot 10^{-6}m^3)=4.5\cdot 10^{-3}kg[/tex]
So, the amount of heat added to the water is
[tex]Q=(4.5\cdot 10^{-3}kg)(2.26\cdot 10^6 J/kg)=10,170 J[/tex]