In a photoelectric effect experiment, radiation is incident upon a rubidium (Rb) surface. Another metal surface is paral

[answerhappygod]

In a photoelectric effect experiment, radiation is incident upon
a rubidium (Rb) surface. Another metal surface is parallel to this
Rb surface such that the Rb and this metal surface form parallel
plate. No electrons are ejected from the surface until the
wavelength of incident light falls below 571 nm.
Part b with answer: If the incident radiation has a wavelength
of 350 nm, what is the potential difference between the Rb surface
and the other metal plate needed to bring the fastest
photoelectrons to a halt.
Answer: 0.263m
PART D: Consider a beam of photoelectrons made of electrons from
part (b). These electrons are incident upon double-slit apparatus
with a slit separation of 1.5x10-8 m. The most
likely place that electrons would land on a viewing screen is
directly across from the center of the double-split apparatus. Find
the angle from the normal to the apparatus that locates the next
most likely place the electrons would land on the viewing
screen.
Need help answering part D please.