observe the flash to last for

$($select$)$

s$.$ The speed at which the light flash will travel toward

you will be $$

Question $8$

$15$ pts

In a photoelectric experiment, Sodium is used as the emitter metal that has the work function of $2\mathrm{.}28$ eV $.$

$($A$)$ The minimum $($cut$-$off$)$ frequency required to liberate electrons from this metal surface is

$[$ Sele Hertz.

$($B$)$ If red light of wavelength $680$ nm is used, the energy of the red photon is $$

$$

eV$.$In this case, the photoelectrons $[$Select$]$ and will have kinetic energy of

$[$ Select $]$ J$.$

$($C$)$ If green light of wavelength of $530$ nm is used, the energy of this green photon is

$[$ Select$]$ eV $.$ In this case, the photoelectrons $[$Select$]$ and will move with

the kinetic energy of $[$ Select$]$ J$.$

$($D$)$ If the intensity of the green photon is tripled, then $[$Select$]$