An electron is to be accelerated from a velocity of

Question

Solve the all parts of given question:

Question: An electron is to be accelerated from a velocity of 3.00×10⁶ m/s to a velocity of 9.00 × 10⁶ m/s.

Part A: Through what potential difference must the electron pass to accomplish this?

Part B: Through what potential difference must the electron pass if it is to be slowed from 9.00 × 10⁶ m/s to a halt?

Please help, completely confused!! Give steps if possible for above question.