Please answer all parts
(13%) Problem 4: Suppose a photon has a wavelength of 2.4 m ? 25% Part (a) Calculate the momentum of the photon in kg-m/s tan() ? ( acos0 sin cosO cotan0 asin) atan)acotan( coshO tanhO cotanh0 0 Degrees O Radians Submit Hint I give up! Hints: 0% deduction per hint. Hints remaining: 1 Feedback: 0% deduction per feedback ? 25% Part (b) Find the speed, in meters per second, of an electron having the same momentum ? 25% Part (c) What is the kinetic energy of the electron in joules? ? 25% Part (d) How does it compare to the energy of a photon? E,JKEe?
Solution
A) momentum is p = h/lamda = (6.625*10^-34)/(2.4*10^-6) = 2.76*10^-28 kg m/s
B) momentum of electron is m*v = h/lamda = 2.76*10^-28
9.11*10^-31*v = 2.76*10^-28
v = 303 m/s
C) KE = 0.5*m*v^2 = 0.5*9.11*10^-31*303^2 = 4.18*10^-26 J
D) Egamma/KEe = (h*c/lamda)/4.18*10^-26
Egamma/KEe = (6.625*10^-34*3*10^8/2.4*10^-6)/(4.18*10^-26) = 1.98*10^-6
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Please answer all parts (13-) Problem 4- Suppose a photon has a wavele.docx
1. Please answer all parts
(13%) Problem 4: Suppose a photon has a wavelength of 2.4 m ? 25% Part (a) Calculate the
momentum of the photon in kg-m/s tan() ? ( acos0 sin cosO cotan0 asin) atan)acotan( coshO
tanhO cotanh0 0 Degrees O Radians Submit Hint I give up! Hints: 0% deduction per hint. Hints
remaining: 1 Feedback: 0% deduction per feedback ? 25% Part (b) Find the speed, in meters per
second, of an electron having the same momentum ? 25% Part (c) What is the kinetic energy of
the electron in joules? ? 25% Part (d) How does it compare to the energy of a photon? E,JKEe?
Solution
A) momentum is p = h/lamda = (6.625*10^-34)/(2.4*10^-6) = 2.76*10^-28 kg m/s
B) momentum of electron is m*v = h/lamda = 2.76*10^-28
9.11*10^-31*v = 2.76*10^-28
v = 303 m/s
C) KE = 0.5*m*v^2 = 0.5*9.11*10^-31*303^2 = 4.18*10^-26 J
D) Egamma/KEe = (h*c/lamda)/4.18*10^-26
Egamma/KEe = (6.625*10^-34*3*10^8/2.4*10^-6)/(4.18*10^-26) = 1.98*10^-6
