Velocity??

Question

Calculate the velocity of an elecrton that produces an ultraviolet light at a wavelength of 250 nm

Answer 1

v = fλ, where v is velocity, f is the frequency, λ is the wavelength.

so this question u'll need to know the frequency of the ultraviolet light. just substitute the values in, making sure that f is in s^-1 and λ in m (meters). v has units of ms^-1

Answer 2

v = h/(250 x 10^-9 x 9.1x10^-31) = 2 916.04396 m/s