Could someone please take the time to do this problem and explain it to me so that I can do other similar problems on my own? An electron moving at 1 percent the speed of light to the right enters a uniform electric field region where the field is known to be parallel to its direction of motion. If the electron is to be brought to rest in the space of 5.0cm, (a) what direction is required for the electric field, and (b) what is the strength of the field? So far I've figured out what 1% of the speed of light is and converted 5cm into .05m. I then used the formula E = V/d to try and get the answer, but it was wrong. What am I doing wrong?