1. The problem statement, all variables and given/known data In a picture tube (eg. a TV set) electrons are accelerated of an electric field. If the electric field strength is 100 kV / m and the electrons travel a distance 0.2 m from rest, what speed will they achieve? 2. Relevant equations E=U/d where E is electric field intensity, U is the voltage and d is the distance. W=qU F=qE (mv^2)/2 = kinetic energy 3. The attempt at a solution I think that the potential electrical energy of the electron will be converted into kinetic energy. Hence: W=qU=(mv^2)/2 or v=sqrt((2qU)/m). The charge and mass of an electron is known and so is the electrical field intensity. If I insert these values in the equation above I will get: sqrt((2*1.602*10^(-19)*100*10^3)/9.11*10^(-31))=1.87..*10^8 m/s. The correct answer is 8*10^7 m/s.