Step-by-step explanation:
It is given that,
Electric field, E = 554 N/C
Time,

Electric force, F = qE
For both electron and proton,


For electron,




Using first equation of motion as :

u = 0

v = 5059600 m/s
or
v = 5.05 × 10⁶ m/s
For proton :




Using first equation of motion as :

u = 0

v = 2756 m/s
Hence, this is the required solution.