Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

(4%) Problem 4: Assume we have a material with a work function of 4.7 eV A What

ID: 2040763 • Letter: #

Question

(4%) Problem 4: Assume we have a material with a work function of 4.7 eV A What is the maximum speed, in meters per second, of electrons ejected from this metal by photons of light with wavelength 83 nm? Grade Summary Deductions Potential 0% 100% max sin() Submissions Attempts remaining: 7 cosO acos) % per attempt) detailed view atan)acotan)sinhO coshO tanhO cotanhO Degrees ORadians 0 END Submit Hint I give up! Hints: 0% deduction per hint. Hints remaining: 2 Feedback: 0%-deduction per feedback.

Explanation / Answer

energy incient E = hc/L = (6.62*10^-34*3*10^8)/(83*10^-9) = 2.31*10^-18 J


1 ev = 1.6*10^-19 J

work function W = 4.7 eV = 4.7*1.6*10^-19


kinetic energy of emitted electron KE = E - W = (1/2)*m*v^2


m = mass of electron = 9.11*10^-31 kg

2.31*10^-18 - 4.7*1.6*10^-19 = (1/2)*9.11*10^-31*v^2


maimum speed vmax = 1.85*10^6 m/s