Dual Nature of Radiation and Matter

Yes, they travel in a vacuum at the speed of light and can never be in still position. This is because they do not have any mass to do so and will not exist only if not in motion.

The key difference lies in not their spelling but the properties they possess. Protons are positively charged particles which revolve around the nucleus of an atom and have a specific mass. Whereas, photons don't have any mass and are responsible for carrying out electromagnetic radiation. They travel free without any restriction.

Photocell works on photoelectric effect.

For no emission of electron

λ > λ₀

Q λ_{0 =} hc/w_0,  so λ > hc/w₀

For no emission of electron

λ > λ0

$\stackrel{?}{F}=e{E}_0\stackrel{?}{j}$

${\stackrel{?}{a}}_y=\frac{e{E}_0}{m}\stackrel{?}{j}$

$=v_0\stackrel{?}{i}+\left(\frac{e{E}_{0}t}{m}\right)\stackrel{?}{j}$

$\left|\stackrel{?}{v}\right|=\sqrt[]{v_0^2+{\left(\frac{e{E}_{0}t}{m}\right)}^2}=v_0\sqrt[]{1+{\left(\frac{e{E}_{0}t}{m}\right)}^2}$

$\lambda =\frac{{\lambda }_0}{\sqrt[]{1+{\left(\frac{e{E}_{0}t}{m}\right)}^2}}$

According to Einstein's photoelectric equation maximum kinetic energy of photoelectrons, $K{E}_{ max }=E_v-\phi$

or   $2=5-\phi$ $\therefore \phi =3eV$

When $E_v=6eV$  then, $K{E}_{ max }=6-3=3eV$

or $e\left(V_{cathode}-V_{anode}\right)=3eV$

or   $V_{cathode}-V_{anode}=3V=-V_{stopping}$

  $\therefore V_{stopping}=-3V$

$\stackrel{?}{F}=e{E}_0\stackrel{?}{j}$

${\stackrel{?}{a}}_y=\frac{e{E}_0}{m}\stackrel{?}{j}$

$=v_0\stackrel{?}{i}+\left(\frac{e{E}_{0}t}{m}\right)\stackrel{?}{j}$

$\left|\stackrel{?}{v}\right|=\sqrt[]{v_0^2+{\left(\frac{e{E}_{0}t}{m}\right)}^2}=v_0\sqrt[]{1+{\left(\frac{e{E}_{0}t}{m}\right)}^2}$

$\lambda =\frac{{\lambda }_0}{\sqrt[]{1+{\left(\frac{e{E}_{0}t}{m}\right)}^2}}$

Photocell works on photoelectric effect.

For no emission of electron

$\lambda >{\lambda }_0$

$?{\lambda }_0=\frac{hc}{w_0},so\lambda >\frac{hc}{w_0}$