Physics
posted by lucky on .
A certain moving electron has a kinetic energy
of 1.01 × 10−19 J.
Calculate the speed necessary for the electron to have this energy. The mass of an
electron is 9.109 × 10−31 kg.
Answer in units of m/s.

Since the kinetic energy is
KE = (1/2)mV^2,
The speed is V = sqrt(2*KE/m)
They have told you the values of KE and m; so do the calculation.