In a photoelectric experiment using a sodium surface, you find a stopping potential of 1.61 V for a wavelength of 320 nm

[answerhappygod]

In a photoelectric experiment using a sodium surface, you find a
stopping potential of 1.61 V for a wavelength
of 320 nm and a stopping potential
of 0.861 V for a wavelength of 396 nm.
From these data find (a) a value for the
Planck constant, (b) the work function Φ
for sodium, and (c) the cutoff
wavelength λ0 for sodium.