Relationships Between Force, Field, Energy, Potential Video Lessons

Concept

# Problem: An electron with an initial speed of 5.30×105 m/s is brought to rest by an electric field.What was the potential difference that stopped the electron?

###### FREE Expert Solution

Law of conservation of energy:

$\overline{){\mathbf{P}}{{\mathbf{E}}}_{{\mathbf{0}}}{\mathbf{+}}{\mathbf{K}}{{\mathbf{E}}}_{{\mathbf{0}}}{\mathbf{=}}{\mathbf{P}}{{\mathbf{E}}}_{{\mathbf{f}}}{\mathbf{+}}{\mathbf{K}}{{\mathbf{E}}}_{{\mathbf{f}}}}$

KE and PE are expressed as:

$\overline{)\begin{array}{rcl}\mathbf{K}\mathbf{E}& {\mathbf{=}}& \frac{\mathbf{1}}{\mathbf{2}}\mathbf{m}{\mathbf{v}}^{\mathbf{2}}\\ \mathbf{P}\mathbf{E}& {\mathbf{=}}& \mathbf{q}\mathbf{∆}\mathbf{V}\end{array}}$

###### Problem Details

An electron with an initial speed of 5.30×105 m/s is brought to rest by an electric field.

What was the potential difference that stopped the electron?