Answer:
moves into a region of higher potential
Potential difference = 835 Â V
Ki = 835 eV
Explanation:
given data
initial speed = 400000 m/s
solution
when proton moves against a electric field  so that it will move into higher potential  region
and
we know Work done by electricfield  W is express as
W = KE of proton  K
so
q × V  =  0.5 × m × v²   ......................1
put here va lue
1.6 × [tex]10^{-19}[/tex] × V  =  0.5 × 1.67 × [tex]10^{-27}[/tex] × 400000²
Potential difference V = 1.336 × 10-16 / 1.6  × 10-19   Â
Potential difference = 835 Â V
and
KE of proton in eV is express as
Ki  =  V numerical
Ki = 835 eV