An electron is placed in an electric field and is allowed to accelerate for a distance of 1 m. If the strength of the electric field is E = 200 V/m then what is the final velocity of the electron, assuming it starts from rest?

Question

ujjwal · Answer

Force on electron, F=eE.......(1)
where e is electronic charge 
and E is electric field
also, 
     gain in KE = work done
or, 1/2 mv^2 = FS  
or, 1/2 mv^2 = eES
$$or, v=\sqrt{(2eES)/m}$$ where m is mass of electron
S is distance traveled by electron
v is final velocity attained 
your answer will be 8.38*10^6 m/s (approx)

anonymous · Answer

thanks, the answer is 8.4 × 106 m/s :)

anonymous · Answer

10^6*