When an electron is accelerated by a voltage difference, the kinetic energy acquired by the electron equals

Question:

When an electron is accelerated by a voltage difference, the kinetic energy acquired by the electron equals the voltage times the charge on the electron. Thus, one volt imparts a kinetic energy of 1.602 × 10–19 volt-coulombs, which equals 1.602 × 10–19 J. What is the wavelength associated with electrons accelerated by 4.00 × 103 volts?