An electron with an initial speed of 450 x 105ms is brought

Question

Compute given parts of following problem:

Problem: An electron with an initial speed of 4.50 x 10⁵m/s is brought to rest by an electric field.

Part A: What was the potential difference that stopped the electron?

Part B: What was the initial kinetic energy of the electron, in electron volts?

I want help to determine the potential difference that stopped the electron.