Question

If a metal with a threhold frequency of 1.1 x 10^15 Hz is illuminated by light with a wavelength of 170 nm, then the maximum kinetic energy of the emitted photoelectron will be?

this is my solution:

h= 6.63 x 10^ -34 J.s
c = 3 x 10^8 m/s
Wavelength= 1.7 x 10^-7 m
Threshold frequency = 1.1 x 10^15 Hz

E max = hc/wavelength + Threshold frequency

E max = 6.63 X 10^-34 (3 X 10^8)/ 1.7 X 10^-7 + 1.1 X 10^15

The answer should be 4.4 x 10^ -19 J

but i keep on getting 1.1 x 10^ 15

Plz can u anyone explain me what am I doing wrong here??

Thank u in advance =)

Answer 1

even if i try
hc/wavelength - Threshold frequency i still don't get the right answer

Answer 2

Your units are messed up.

On the right, energy + frequency?

convert the threshhold frequency to energy or...
Emax=h(c/wavelength - frequency) should do the work.