Speed of the electron after the collision

[Foshizzle387]

An electron with a speed of 5.50×10^6 m/s, collides with an atom. The collision excites the atom from its ground state (0eV) to a state with an energy of 3.50eV


What is the speed of the electron after the collision?


Dont know where to start.

 

[rock.freak667]

Well how much of the initial energy of the electron is transferred to the atom to cause the excitation?

 

[Lil_Aziz1]

Conservation of Energy:

$$KE_e_i = KE_{e_{f}} + E_{atom}$$ assuming that the atom is initially at rest.