A beam of electrons is accelerated from rest through a potential difference of 0.100 kV and then passes through a thin slit. When viewed far from the slit, the diffracted beam shows its first diffraction minima at+-14.6° from the original direction of the beam. (a) Do we need to use relativity formulas? How do you know? (b) How wide is the slit?

A beam of electrons is accelerated from rest through a potential difference of 0.100 kV and then passes through a thin slit. When viewed far from the slit, the diffracted beam shows its first diffraction minima at+-14.6° from the original direction of the beam. (a) Do we need to use relativity formulas? How do you know? (b) How wide is the slit?